If you have a matching numbers (original engine, transmission, and rear end) Shelby GT500, and it's restored to how it was originally, the car will be worth at least $120,000. Easily, if it has a quality restoration. You should restore it to original condition, cuz if you don't the car will only be worth a fraction of that amount, and it would be a shame. A quality restoration on a Shelby is ridiculously expensive, plan to spend a minimum of $90,000, since you only have the body and motor. Original steering wheels for them cost $8,000, reproduction ones cost $2,000. If you a want crappy restoration, just good enough to be drivable, plan on spending $18,000.
Are you restoring it just to make a profit? Most cars never get out of them what you spend fixing them up with. Go as original as possible but you will pay out your butt just for the shelby name. You will reach 100k easy if it is accurately done. Original everything. Every detail counts to collectors. Wiring, plumbing, hoses, decals and stickers, chalk marks on the underbody and frame, seat belts. You will spend allot of money. Be prepared to not drive it for a good couple years unless you have tons of money to dump into it and a good mechanic and body man that will do the work without taking long breaks from it. Best thing for you to do is stay as far away from the Eleanor look as possible. Dont go down that road. Great Find!
It could cost a bundle.. You should be more enclined to restore this to its original condition if its a true Shelby GT500, it will reatin and increaser in value. I have seen these cars fetch a premium price at auction and have restored a couple years ago with Drew Alcazar.