One piece of advice that I'd recommend following...
If someone is selling a "restored" or "solid" car...ask them for before and after pictures.
Other experienced car guys all thought my car was "solid"...right until I stripped it down for a frame-off.
I found fiberglass fillers in the floor pans, rust in the toe boards and rockers, etc.
I now have pics of the rebuild of my car, showing installation of the one piece underbelly that went from firewall to the rear valance, including rear frame rails, etc.
So when I say the car is "rust-free"...I can prove it
Bottom line, if you don't have that documentation, be prepared to do a frame-off to get it right. That may be worse case scenario, but it's real. Without pics, everything is unknown...and you can spend a LOT of money and a LOT of time getting it safe and right.
My body shop called me over one day and showed me the rear shock towers, that had looked pretty solid before media blasting. It was clear that if I had really launched the car, the shocks would have probably gone through the rear windshield