what to do if you have the "lost" car

I am concerned because locally there is a man who bought a 70 swinger brand new. And he had the vin number and was able to track it, however when he tracked it down his search led to my front door because I now own his old car.

The problem is that he wants to buy it back but its not for sale. I bought the car 5 years ago and gave it to my cousin and it was paid for with cash and everything was on the up and up with the papers.

This man is trying to guilt me into selling it back with a sad story as to why he sold it, and he is making it seem like I have something that belongs to him and keeps dropping by every once in awhile. But is was him who sold it years ago and it went through 2 other owners before I bought it. So it was his own will and choice to sell it years ago and as far as I knew, when you sell something it is gone and you got your money so its over.

At one point I asked my cousin if she was interested in selling it before she was made aware that the original owner is trying to buy it back. I figured if she would part with it then I would sell it back and make everyone happy. The problem is that she likes the car and I don't see how its fair to take it away from her to make someone else happy who chose to part with it years ago, for whatever reason which is irrelevant now.

What do you guys think about this situation and what would you do?
what is one supposed to do if you have the "lost" car or engine or anything like that?

I'm only going on this post.
Reuniting is only a good thing if everyone concerned is happy about it.
This is a case of car stalking.
Swear out a restraining order against him.
Your car's safety could be in jeopardy.(Only half kidding)