A bit of an update and progression
It now looks like this;
The bulkhead just crumbled, as did the door that you can see., HOwever, the chassis, although in need of rear cross member and outriggers, isn't as bad as I thought
Replacment chassis has had its bulkhead removed and gone to paint man. It is sitting on the old 2a front axle which has now had new seals and a fetching pair of gaiters.
Waiting for the LT77 to turn up and then the fun to start regarding how that is going to fit.
On the plus side, the right (off side) side frame looks to be good enough for re-use. I will be getting a replacement near side though.
Just picked up another 3.54 diff so I now have a pair!