One of the most interesting "Elvis and his Guns" stories I've ever heard is one I got at a Dallas gun show. There was a dealer there who had a few large tables displaying some highly collectible and expensive handguns, many of them in nice glass cases with their accompanying letters of authenticity. One of them was previously owned by Elvis. When I inquired about it, the dealer gave the following account.
It was a revolver (a .38, I believe) that was in a case, and had a handwritten letter from Elvis himself. The story behind it is that Elvis would often send one of his bodyguards or assistants to his bank, if he needed to make a night deposit to unload some cash. Apparently he decided one night that he needed to make such a deposit, but for whatever reason no one was available except for an older housekeeper, a woman who had been with Elvis for a long time.
He asked this housekeeper to make the deposit, but when she hesitated Elvis retrieved the nickel plated (as I remember) revolver, handed it to her and told her to take it for protection. She balked, and when she did, Elvis wrote out a note which said that this woman was employed by Elvis, and was authorized by him to carry the handgun for her own protection. She did his errand, and Elvis gave her the revolver to keep, which she did for years in her own home long after his death. In fact, she kept it mouinted on a wall of her home.
As the years went by, her health suffered until one day, she was sent to a nursing home. Guess what she had mounted on the wall of the nursing home, next to her bed?
Elvis or no Elvis, that piece of memorabilia wasn't allowed by the nursing home in such a public display, so they made her take it down. Finally, either the housekeeper or her family sold it off, as they needed the money. It finally came to be owned by the dealer who told me the whole story. IIRC, he told me he has been offered as much as $30k for the gun (which has the original "permission slip," written by Elvis himself. He's refused all offers, but I'm sure that at some point someone will wave enough dough in front of him to let it go. It was a fascinating story, and seeing that revolver encased like that, with that handwritten note was very impressive.