Oh, boy. Where do you start?
First is body. That will kill you if it isn't good. Rockers, sills, rear spring boxes in body (forward of axle), take an ice pick.
Lift the carpets, stab the floor, especially under pedals. Bottom of the rockers. Inside of the sills (vertical above floor), if he'll let you, pull the spats, get a better view of the spring boxes.
Pull the spare out, lay a flashlight under the well and look inside for holes. Poke the well with the ice pick.
Do NOT try to start it. You don't know if the valves have rusted to the guides, fuel is varnish by now, lubricants need to be changed.
Look at the block core plugs (LH side of block, under and below exhaust manifolds) to see if they leak or are pushed out. Exhaust is probably rust donor.
Fuel tank may need patching..any moisture pooled at the bottom and rusts it out.
Wood....will cost you a lot to have fixed if bad. If just finish, you can do that yourself, but if it's delaminated, hang on to your pocketbook!
Leather...any good or rotted?
All the bits there? Chrome strips, leaper, lights and surrounds/
Look and post your findings, we'll narrow the parameters based on what you find!
Good Luck!
Dave