Above are two photos of the same weapon, which has recently been through my hands (for repair). Quite small, it has a sixteen inch brass barrel, a flintlock, and a walnut stock. It is, of course, very much a military piece (note the 'brown Bess' layout and proportions), and was probably for naval use. It was made about the year 1780 to 1790.
I must say that I learned a great deal from the gun during its repair.