Not all hopes are dashed.

 I spent some time stripping the last of the useful parts from the parts car a few days ago. I now have spare blower fan assemblies and a complete Delanair climate system. Interestingly, I found what appears to be an aftermarket amplifier for the Delanair system, it's in a plastic cylinder and plugs into the factory original plugs.
 So, the interior is almost complete. The door trims haven't been started yet as I need new door cards. I have seen them new somewhere, but can't find them right now. They can wait, still plenty to do.
 I am lucky enough to have two complete dashboard assemblies to choose from to restore, the one that came with the car is in very poor shape, it's seen a lot of direct sun exposure from sitting in a paddock with no windscreen to filter the UV light.
 The parts car one was much nicer, but still had some splits here and there. You can see how much worse off the original is compared to the parts car one, original to rear:

After studying the dash for a good, long time, I thought it might just be possible to have a go at a reskin.
The factory uses an unbacked vinyl and vacuum forms the vinyl onto the frame and foam, but most of the curves seemed gentle enough that I could get away with it.
 The first step was to remove any vinyl that was delaminated, clean up rough corners then fair and fill the cracks. I faired the cracks with a flap wheel disc, then filled with urethane adhesive. The urethane works well, it stays flexible, is a super strong adhesive and it can be applied and sanded fair like any body filler. It just needs absolute cleanliness to work. Dug out cracks and faired with flap wheel:

And then applying urethane and sanding. The urethane is very easy to apply being single stage, and comes in a caulking cartridge, so easy to force into the crevices:

And the finished product:

 The scary part was working out how to skin the dash. You don't want to stretch the vinyl more than you have to. The more you stretch now, the more it will inevitably shrink as it ages.
 Of course, you have no choice in certain areas, but they are generally areas that are convex curves, so if they shrink, they only pull tighter.
 Don't even attempt this unless you have a way of spraying proper industrial contact adhesive, you need good, thick coverage and the adhesive needs to soak into the vinyl backing scrim for a proper bond. There's no glue in a can that will last and brushing it on is too inconsistent. I sanded the existing vinyl down heavily with 240 grit on a detail sander, ideally you want as much oxidised vinyl removed as possible. Then wipe down several times with a quality wax and grease remover. We are relying completely on the contact adhesive bond, we want it as strong as possible!

 So, here's as good a place as any to start, lay the top down, then fold back, spray some more adhesive on and slowly work your way down. You WILL need a heat gun to do this:

Keep working it, slowly, no rush. A bit at a time. It's OK to stop and have another go! I did, several times. Stick a bit down, glue some more, heat with gun, stretch and glue. And so on:

I would say the job was pretty successful, although there was a solid six hours all up in it. I'd give it 90%, next time would be much easier!
 Here I am trial fitting the defroster fill piece and windscreen rubber, defroster piece needs some shimming and tweaking to fit better. Notice some slight bubbling around the tight corner where the gauge binnacle meets the flat part of the dash. This should bubble evenly around this corner as everything settles and look much smoother. If I was to do it again, I'd fill this corner to a bit of a radius using the urethane. I thought about putting a seam in the vinyl here, but then I would've needed to skin the dash with foam and that wouldn't have allowed near as good adhesion of the vinyl:

Aftermarket screen rubber looks like it will work nicely too, and most importantly, meets up with the interior trim neatly everywhere as well:

Whilst the dash was apart, I mix & matched the two switch panels I had to make the nicest one I could with parts. I scored a NOS Hazard lamp switch some time ago and will replace the others as they come up for sale. Meantime, they all got disassembled, cleaned and regreased. I really should've found some silver paint and run new borders around the switches, but I do intend to buy new ones and my hands weren't feeling very steady on the day:

 I also scored an NOS filler flap seal off Ebay. Unfortunately, there was some slight aging from it being stored in a PVC bag (some rubbers seem to react with PVC long term), but it cleaned up nicely and the surface stickiness has gone. It really finishes the fuel filler surround nicely and prevents the filler flap damaging the paint:

No photos, but I've pulled the Cibie headlights apart to see what needs to be done. The lens had already separated off one, so I knew the reflectors were in bad shape, but the rest is in very good condition, no corrosion. The plastic diffuser inserts are very yellowed though, I'd like to scrounge up some new ones if I can, or I may try my hand at making a mould and finding a suitable resin to cast them in. There are some super clear acrylics out there for encapsulating things, but I'm not sure of their UV resistance.
 I kicked about a few ideas on how to restore them, including inserting later model lamps, but it's going to be cheaper and much easier to get the reflectors replated. I have a lead on a company that can do the vacuum metallizing process for a reasonable price and they also plate plastic. So I will get the headlights stripped and cleaned and send them off with the tail lamp bezel/bodies for replating when I can allocate funds for that.
 The last big looming job to do is to work out how to refinish the urethane or rubber bumpers. The surface is too sun damaged for a simple sand and buff, I may end up having to apply another layer of urethane somehow. I'm considering spray on bedliners, urethane adhesive like I used on the dash etc, but the real trick will be finding something slow curing and with the right flow characteristics to make the job garage friendly.
 The list of really big jobs is just about finished, now there's lots of smaller tidy up and finishing off jobs to be done. In my experience, this is where things can bog down if you let them!

Recline and console yourself.

 With the rear seats and side panels done, it was time to move on to the front seats.
 Frankly, after I disassembled the stock XJS front seats, I found them quite underwhelming, especially for what was supposed to be a grand tourer. Very underbuilt frames, virtually no support, rubber diaphragms instead of springs, a poorly shaped back rest. The XJ sedans have far, far superior seats....
 Anyway, I had been hunting for a nice pair of used seats that would be supportive, fit in the XJS and not look too modern. As the XJS is only a relatively small car, the backs couldn't be too high, nor could they be too wide, as the XJS has very large sills and a fairly wide and high transmission tunnel and console.
 Eventually I found a pair of series 4 RX7 seats that were complete, looked OK style wise and being from a small sports car, should have fit in the XJS. They also have the huge bonus of having a decent, adjustable lumbar support for driver, adjustable headrests and the passenger seat has a tilt forward pedal for rear seat passengers. Plus, the seats have actual steel springs, instead of the stupid rubber diaphragm, which means extra support where needed!
 They are a perfect fit. Here are some photos of me mocking them up into the car:

As you can see, they were old and filthy, but complete. So, onto modifying the bases and retrimming them.
The RX7 seat base frames were pretty simple, the bases were dead flat in the mounting plane, except for the driver's side inner, it kicked up a bit, to clear something on the RX7 floorpan. I had to make short legs to compensate for that, but the other six mounting points were very close to the stock XJS mounting points. It only required some flat plate about 2" long to be welded flat to the base of the RX7 seats and drilled to suit the XJS tracks, and the tracks then bolted straight on. Very easy.

Bases patterned up and laid out for assembly:

And base with new skin stretched over for a trial fit. Note that I carried the fluting over from the back seat, makes the seats look factory!:

Completed base:

As you can see, the RX7 seat is also very low, as per the XJS seats, so headroom is not terribly adversely affected. I would say the seat cushion sits about 1" maximum higher than the stock XJS seat.
And the pair completed, but without headrests:

Installed in the car, they really do fit quite well. Enough clearance for hand brake, console and the seats with headrests tilt and slide forward without catching the headlining:

So all in all, a great and easy swap.They are extremely comfortable as well.
Next on my hit list was the centre console. I had 3 to choose from, two very early ones and a later one. I chose the later one as it was the least warped. Jaguar stretched the vinyl onto the earlier consoles without using a seam for the contours, and it pulls the sides of the console out over time.
Here's some photos of marking up and the final console. Not too much to comment on, except that I deleted the rear ashtray for a cleaner look:

I also retrimmed the A pillar kick panels. They were fun, the old cardboard was a bit warped, but the relatively heavy carpet I used has flattened and stiffened them up nicely. Of course, once they are screwed into place, they will be nice and straight anyway. I prefer these early kick panels, they have a more custom look than the later vinyl/ leather trimmed ones:

Take a seat.

 But first, in the my god, does it never end/ cascading jobs needed before doing something else department, I wanted to install the door glass.
 To do that, I needed to install the door quarter vent glass (previous post) and re run the door wiring. Now, the door wiring boots for the XJS are no longer available new and the old ones disintegrate as soon as you look at them funny. I've also been leaving the front guards off so I could sort out the wiring.You can see how one small job can hold up work over a large area on a project!
 So I made some new cable boots using generic, cut to size boots, split tubing and heat shrink tube. They turned out way better and less cobbled together than I expected:

 Once that was done, it was back onto the interior. I got the headlining and pillar trims sorted out easily enough. Again, this colour of headlining is just not available in Australia, it was one of the materials I ordered from the US:

Then, onto the seats. I foamed up the rear seat base and back, this helps smooth out old seats and hides all those small imperfections old foam accumulates over time. If you look closely, you can see that jaguar was still using coconut fibre as a padding material in 1977:

Then it was onto the marking up and cutting out:

Trial fit:

Rear seats finished. With this type of material, having a foam backing, it's normal to initially have a few stubborn creases that won't pull out. They disappear over time as the foam relaxes and the material finds it's own levels:

 The quarter panel trims on an XJS, they are a nightmare! So many sub assemblies and small parts. No wonder Jaguar couldn't make money on these cars, way too labour intensive to produce
 All these pieces:

To make this (yes, my parts car had a dark green exterior and a dark brown interior. The 70's were unkind to vehicle interiors...):

 I added some cedar I had laying around to the pockets because they had gotten wet and warped, plus I wanted to fit speakers and wanted them a bit stiffer:

 Needless to say, as with every other piece of interior trim in a 40 year old XJS, the quarter trim casings were cracked, torn and damaged. They needed some help with realignment and some fibreglass:

The quarter panel cases are covered with one piece of material, it's a long, tedious process getting it stretched into place and looking right! Each side would have a solid four hours in it:

 I'm still working on the interior, the door trims are disassembled and being flattened out, more pics and an explanation in the next installment!