Doubt very much that this was ever a pinfire .Question I ask is about the stock .Looks far to good for a gun of its age , so it has IMO either been very carefully renovated and re checkers or re- stocked in recent years .
Holes in the bottom ribs and tail piece/short rib suggest rust and possibly a re-soldered loop and that the barrels have been re- browned .Possibly a little leakage in doing so have had these drain holes drilled . Not uncommon .
My opinion from the pictures is that the stock is original but has been refinished at some point. Recent is a relative term for a 150 year old gun. I own two Scott guns from almost the same year and they both have wood and metal in as good a condition as this. All appear to be hard and durable wood. One is an 8 gauge single who numerous experts have deemed as nearly mint. The other is a lightweight 12. I believe the 12 had been refinished but the 8 single is original finish. There is a difference in the look. This gun has the original buttplate that fits perfectly and looks period and old. My best guess was that at some point (50's/60's?) the gun was rehabbed with the barrels repaired and refinished and the stocks refinished and repointed. Likely not used much since then. Actual bore measurements will tell the tale likely as to how much was done.
This sort of thing would have been normal in England where the originality phobia of working guns doesn't exist. I got the gun at what I think was a bargain price, so not bothered by that. I always choose proper working gun in good shape every time over a pricey delicate piece that has it's carefully preserved problems. The truly high grade museum pieces I stay away from because I know I will use them and don't want the responsibility of owning them.
![[Linked Image from i.imgur.com]](https://i.imgur.com/rJhco45.png)