B.M. Bosworth
New England Underhammer Single Shot Pistol, By B.M. Bosworth,Warren, Rhode Island, with Rare Grip Compartment.
circa 1850s.
.31 caliber, 5 7/8 inch part octagonal, part round heavyweight barrel, with brass pin front sight; the left side of frame marked in an arc, surmounting a sunburst: B.M. BOSWORTH; brass frame with steel hammer and trigger; cast brass frame with hinged left side to bag-shaped grip, opening upward and secured by pin in butt.
Many thanks to "GREG MARTIN AUCTION" for the photos.