Only around 1,000 of the Wesson & Leavitt Belt Model revolvers were manufactured by the Massachusetts Arms Co. in 1850 and 1851 before production was halted due to a patent infringement suit won by Colt. The design was in part by Edwin Wesson, older brother of Daniel B. Wesson of later Smith & Wesson fame. The younger Wesson and Horace Smith were among the incorporators of the Massachusetts Arms Co. In addition to the standard markings and cylinder etching, this revolver has higher quality engraving and silver plated trigger guard, grip washer, and back strap. "921" marked on the back of the barrel "barb" and face of the arbor pin. "659" marked on the underside of the back strap, on the right of the grip beneath the lock, front flat of the grip and front and rear flats of the frame.