Opinions on value of '66 Valiant with 273 Commando

What do you guys think I should offer for a ’66 Valiant Signet two door hardtop that I found? I would like to make an offer that is fair for both the seller and myself but I’m not sure what a fair value would be. I know it’s all about the condition so here’s what I know.
Being sold by the original owner who ordered the car but it has not been running since 1978, he’s looking for offers. It has over 125,000 miles and still has its original 273 commando engine with the exhaust still, it even has the chrome tip on the resonator but it’ll need to be replaced. Other than the engine there’s nothing too special about the car - it has a bench seat and a 7 ¼” rear axle. The interior isn’t too bad other than rips on the drivers side seat cushion and passenger side sun visor. The vinyl top is almost completely gone, the paint is very thin and there looks to be some surface rust. There are small rust holes in the front fenders at the top and lower portion, the doors have some small rust holes too. Quarter panels have some small rust holes and there’s one in the trunk too but floors and trunk seem solid. He’s going to check out the frame and torsion bar mounting for me, let’s assume they are good for now. So there’s a lot of body work to do plus I know the brake and fuel system will need to be almost completely replaced. The brake work is ok because I would probably put on front disc brakes anyway but the gas tanks and fuel lines I’m sure are wasted. I'm sorry I don't have pics to post but there are some on this link ==> http://mysite.verizon.net/vzes9hbq/sitebuildercontent/sitebuilderfiles/66-valiant-forsale.pdf