I think the Proof Marks are Brumingham 1855 to 1868 ?. Nothing wrong with that of course.
As previously posted this is a 14 bore, not a 10. Many of these were chambered as a 12 and usually have loads of meat in the barrels if you had to lap out for reproof.
Couple of queries for me tho, that side lever does not really match the hammers in profile, would have thought it should have been finished 'round' and also the ivory bead. Dont know if that is original and my puter skills are not good enough to get a decent close up of the muzzles, certainly looks like there is plenty wall thickness there.
Not a bad looking old gun though. Must have a look for B,ham maker or barrel maker AB, that should help to pin it down.
