Manufactured circa 1857 to 1860. The top of the rib is marked "SMITH & WESSON SPRINGFIELD, MASS", faint patent marking on the cylinder and the matching serial number is marked on the butt and on the inside of each grip panel. The matching assembly number "12" is marked on the rear of the barrel lug, cylinder and left frame heel under the grip. Standard blade front and notch rear sights, the barrel and cylinder were blue, with a silver plated brass frame and fitted with smooth rosewood grips.