Bryan,
Thanks for the reply.
I agree that the horizontal dimensions won’t be needed. The floor pan is in good enough shape to maintain lateral stability. The inner rocker, as much as I can see, has some significant rust. The repairs my father-in-law made have performed well. And if anything, judging by the door margin, he may have over compensated and the floor might have a slight bow up.
My idea was only to remove those items necessary to execute repairs: carpet, seats, various interior components, and front fender. I was going to leave everything else intact for now, including the drivetrain and door. (Unless I find I have to take more apart to get the new parts in place.)
While I believe the horizontal dimensions are okay, I am concerned about the vertical dimensions. The jig I have in mind would be based upon the Liskey frame dimensions with the addition of adjustable leveling feet at each vertical support location. There would be 8 vertical supports that the frame would set on. I can then cut loose the inner rocker, torque box and other affected areas without fear of the frame sagging any further than factory spec. And then use the leveling feet at the post locations to fine-tune the dimensions while watching the door margins as you suggest. The outer rocker would remain in place as an original spacer. I don’t think I’ll have to replace that piece. Once I have the optimum combination of frame measurements and door opening margins I can begin installing the new sheet metal.
Spot welds will have to be drilled out with a spot weld drill. I think I can plug weld the new components at these locations and dress the welds to try and maintain a factory original appearance. On the floor pan components I was thinking of preparing the patch panels for butt welds and dressing them to provide for a smooth original appearance. I can also spot weld areas that would originally have been spot welded. Maybe I can keep the evidence of the repair to the bare minimum?
I can’t say with certainty that the car has NEVER been wrecked. I only know its history since the mid-eighties. For instance, as I said above I had to remove the front fender. The Car, since I know it, has always had a rear-mounted radio antenna. I expected to see body work on the inside of the fender where the radio antenna should have been mounted – but there was none. It’s a pristine front fender without an antenna hole. I suppose the dealer could have mounted the antenna on the rear instead of the front. But there’s also the possibility that the fender was replaced. I need to check out the date codes to verify which scenario is more likely. I’ll try to post some pictures later and maybe we can figure it out?