I really like the flavor of this gun, the execution, the wood, the story, carving, it's evocative of guns you might have seen in my neck of the woods, upper Hudson Valley, near the Mohawk region. Dutch, English, French all vying for power thru trade in alcohol, firearms, iron and brass goods in exchange for land and furs and power.
The humped breech is often seen on rifles and fowlers from this era.
I see where you are going with the hump in the breech, but I think there are a couple of architectural issues with it. The lock does not quite have enough curvature, or banana, for this much bend. It causes the lock to be rocked back to fit the wrist, with a slightly awkward angle. Also a little more banana in the lock would have made the sideplate sit more comfortably in its panel on the other side. More banana in the lock would have allowed the breech 'Hump' be carried back into the tang a bit farther, with a little more radius. Currently, the bend occurs right at the joint between barrel and wood.
And thanks for posting your work.
Tom