When my grandfather passed, my uncle inherited his gun collection (14 or 15). As a favor to my uncle, I sold them for him for a commission, and from this bought some. Two newer hand guns, and old rifle, and two old shotguns. On occasion I shoot the handguns and rifle. I don't have a good place to shoot the shotguns.
I keep all but one shotgun locked up in a gun cabinet. It doesn't fit in the cabinet, but as I was reading this thread it occurred to me I could remove the barrel and then it would fit fine. It stays unloaded under my bed. I'm hoping the pump action would be enough if I ever had a break-in, although honestly, I'd probably forget it was even there.
The shotgun under my bed was my great-grandfather's. I have a black and white picture from the 50's with him holding it. He was a farmer and used it for hunting birds.
My other shotgun is an "unfinished" shotgun. It is missing two stamps on it, the manufacturer's stamp and the inspector's stamp. It's a German gun, and the owner of the manufacturing plant was Jewish. When Hitler started rounding up Jews, the owner fled to England, closing the plant. By my best guess, this gun was near the end of the line when it closed, and probably a worker took it home with him. The gun dealer who found out most of this info for me, found another of the same year with it's stamps. The inspector stamp has a strong connection to my last name. Although that side of the family has been here since the early 1800's, so I'm not sure how my grandfather's family would have any connection to relatives in Germany.
When I sold the other guns, there wasn't really requirements on me because I'm from Alabama. But I found a information sheet online, and got basic info from each person I sold to. Mostly CYA.
My grandfather also had an old shotgun with an 8 in barrel. He might have had paperwork for it, but I never found it. I didn't realize what it was until after I brought all the guns home, going through 4 states, I thought it was an old pistol. If I had paperwork for it, it would have been his most valuable one, but I turned it into the police.