This will be a longer post, mainly because we have made pretty good progress since the last update, so there is lots to cover. The interior has been fully stripped, bare metal everywhere with some soundproofing material still glued on in a few places. The stock soundproofing was very brittle and haphazardly slapped on with large gaps in between so at some point we are going to put in modern stuff with better coverage. The car looks mostly the same as it did last update, just a little cleaner.
The floor pans are coming along, with most of the driver side metal cut out. The frame underneath had drain holes, so it hasn't rusted like the floor pans did. So while the frames seem solid, the pans above them are very rotted and feel as if you could kick through them easily. But as you can see above there is still plenty of solid metal. If you draw a line from the seat mounts to the other side of the car, everything forward of that line is pretty bad while everything rear of the line is solid enough to keep.
Luckily there is enough solid metal to weld the new stuff to, but there is still a ton of rust. When I started sanding down the rust spot in the truck it just kept getting larger until it became less of a spot and more of a hole in the side of the car.
Once again, there is still enough solid metal that chemically treating it and filling in the holes will be passable (hopefully). While the rust has been a challenge, some things are coming along better. There has been no pressure in the brake or clutch since we bought the car so yesterday we tested the brake and clutch master cylinders. Surprise, both are dead. The brake cylinder has some kind of gunk (I'm guess decade old fluid mixed with water) in it and has rusted. It is probably repairable but since we are already ordering a new clutch cylinder we threw in a new brake master cylinder. The clutch is a bit more broken, as the plunger just flops around and won't generate any pressure.
The rear axle and diff are out of the car, and currently sitting at a rear end shop that has promised to get the diff working correctly. They will also bring the rear drums up to something approaching modern spec.
Once the new parts come hopefully it will just be a matter of flushing the lines rather then replacing them. After that, the clutch and brakes should start to work. By then the rear axle and differential should be back from the shop and the car will be able to drive in and out of the barn. That's assuming nothing else goes wrong, which it almost certainly will.