Hey /k/, long time lurker never posted before. Need help identifying a weapon.

My family recently got put into a will from a recently passed woman who didn't have any surviving relatives, we split half her things between a friend of hers and ourselves.

While we were looking through some drawers we found this (In the picture,) and I can only assume it's a home-made pepperbox pistol.

The grey box lookin thing is about 4 inches long and has a wooden handle, very crudely made and doesn't fit well in the hand which is why I assume it's home-made. Trigger's just a verticle bar, slightly indented on the front and back. in each of the four barrels there's something lodged inside, each barrel having the objects at different distances from the end. There's no magazine or load point I can find other than the muzzle, so it's probably muzzle loading.

Haven't tried firing it in case it explodes.
Any ideas /k/?