I dutifully turned in a handgun I found as a young kid. It netted me $50.cash, which I turned around and used to buy a Ruger MkII from a buddy.
The pistol I turned in was a Hopkins & Allen .32, that I found when digging a hole in my folk’s back yard. Totally rusted, and inoperable, but cleaned up good enough to convince the “buyback experts”.
Great story.