Reportedly 2,100 of these Colt Model 1860 Richards-Mason conversions were manufactured circa 1877 and 1878 as cartridge revolvers using a mix of percussion revolver parts on hand and newly fabricated components. They are one of the scarcest Colt cartridge conversion revolver variations and were manufactured concurrently with the famous Colt Single Action Army. The revolver has the distinctive breech plate without a rear sight, a loading gate (1005), and a hammer with the added centerfire firing pin and notch rear sight. The top of the barrel has the one-line New York address. The two-line 1871 and 1872 patent dates are on the left side of the frame, and "44 CAL" is on the left trigger guard shoulder. Matching serial numbers on the barrel, frame, trigger guard, and back strap. The matching partial serial number "916" appears on the cylinder. It is fitted with a smooth one-piece walnut grip. Included with the lot is a U.S. C. Roby 1860 Light Cavalry pattern sword, 41 inches overall with a 35 inch double fuller blade marked with the C. Roby address on the left ricasso and "U.S./1865/A.G.M" on the right, two-branch brass guard and pommel, wire wrapped leather grip, braided yellow and blue tassel, and an iron scabbard.

Fine, retaining 70% "frosted" period retailer nickel finish with a smooth gray patina on the balance. Most of the cylinder scene remains. The loading gate spring is absent. The refinished grip is very good with chipped toes and a few minor handling marks. Mechanically excellent. Sword is good as cleaned, with edge nicks, mild pitting, and light scuffs and handling marks overall.