Does anyone have advice on how to find the original owner?

A friend is trying to locate the first owner of his Super Bee, and we haven't figured out the best way to find out who it was.

I suggested a private investigator, but that could get a serious bill, and no one really has cash to burn.

Have any of you found a simple or easier way to learn who has owned your musclecar, race car, or hot rod? Particularly the first owner. I think a lot of us would like to know if they have photos, paperwork, or memories about the new owner experience of what you now own