Found an original 340 car in a shed

Cool story, Mike.
At least the car still lives and hasn't been stripped and crushed like so many of them were back in the day.
As for if he will ever restore/fix it up, it's his car and he has the right to do with it what he wants.
Maybe if you talk to him again, tell him all of the body panels to restore the car are available through AMD, so it could be easily restored now!
Keep giving him nudges like that and maybe he will bite the bullet and do something with the car instead of letting it sit.
Tell him it doesn't have to be perfect for him to enjoy it again!