Well Ill Try! On how you have described it. I think if it has a good soild frame, no rust, has all interior parts,( like seats, Steering wheel, the doors are still their) and the the apolstery is in good condition. Theirs no engine and tranny. I would estimate it to be a vaule of like $3,000 or less. I mean as long as the frame isnt falling apart or the doors arent coming off or the windows arent shatered. I mean if their is rust and things are coming off. I would sell it for cheaper. If you really want to be sure you can go get it apparised at a dealership. Or definatly ask a dealership. "Where can I get my car apparised". Or possibly you can look it up in Yellow Pages. Of course im a idiot and forgot that you have no engine to even get to a dealership. You can always ask them and see what they say over the phone.
I Hope this somewhat helps
-Good Luck!!