Barman's Percussion pistol takes the cake.
All I've got with a lot of character is a Remington model 12CS. Chambered in .22WRF (AKA .22 Remington Special). Manufactured 1928. Came into my family by way of my great grandfather, then to my grandfather. Grandad's not sure where his dad got it, but we think it may've been collateral on a loan, as some others showed up that way. Dad grew up shooting it, and I've got it now.
It's Been around a long time. I've shot it a few times, but I've decided to retire it now. Someday it'll hang in a glass case with a few rounds of despicably-hard-to-find-ammo.
When it came to me, it hadn't been touched since the last time my dad cleaned it, over 30 years ago. Kinda rusty, and really nasty, but I've more or less brought it back.