Monty, the hammers were never part of a pinfire, they don't even extend over the breech end of the barrels far enough to have ever punched a pinfire. The setup for the firing pins is typical Westley for the time period. The barrel finish is original. The bore diameter is most likely as made. There was no standard and that's sure in the ballpark. And quit worrying about cylinder bores--you're going to find the lack of chokes on your decoyed birds to be a big help.

It's day 8 on the river Maim in Bavaria. My "new" Dougall 10 bore will be in next week. We will have a lot to talk about!

When an old man dies a library burns to the ground. (Old African proverb)