It’s definitely been used. The grip is in decent shape so I don’t think anyone used it for a hammer but I also suspect that it’s never seen the inside of a holster.
If the bore is in decent shape, it's likely a shooter, 7mm pinfire, belgium proofs, IIRC 1880’s from the marks, antique & curio exempt both from age and pinfire cartridge. Last time I saw the rounds for sale, they were asking about $20 for 5.
Best use for something like that is shadowbox it into a case with some old playing cards and chips and a good gambler photo and you'd probably get $350 for it, $500 at a good venue (western show, rodeo, etc.)