Manufactured from 1860 to 1868, this Model 1 2nd Issue revolver has the rare "2D. QUALITY" marking on both sides of the barrel. This marking indicated there were slight casting flaws when the revolver was manufactured. The manufacturing flaws did not affect the mechanical function and they were sold at a discount. Approximately 4,402 of these types of revolvers feature the "2D QUALITY" marking. The barrel and cylinder have matching assembly marks which differ from the marking on the grip frame, a not uncommon feature on 2nd quality No. 1s. The right grip panel is numbered to the gun.