Total production of these U.S. Richards conversions is estimated at around 1,200, and any example in high condition is very hard to find, especially the exceptionally scarce U.S. contract revolvers like this one. These conversions are important pieces in the evolution of Colt firearms and bridge the gap between the iconic percussion revolvers that established Colt as the name associated with revolvers and the Single Action Army revolver that became the most iconic handgun in history. The Richards conversion was patented by Assistant Superintendent Charles Brinckerhoff Richards at Colt in July 1871. He also patented the design for the Colt Cloverleaf House Model that same year and worked alongside William Mason, the superintendent, in designing the famous Single Action Army. The revolver has a slightly shortened barrel which likely happened at the arsenal during to the conversion process before it was plated. The barrel has the one-line New York address on top, and the left side of the barrel lug has "US" and an "A" inspector's mark for Orville Ainsworth. (Ainsworth also famously inspected the first Single Action Army revolvers which included those issued to Custer's 7th Cavalry, and these conversion revolvers were also used in the Indian Wars of the post-Civil War era.) "COLTS/PATENT" is marked on the left side of the frame. The 3-screw frame is cut for a shoulder stock. The cylinder has the naval scene and "AP" U.S. markings. "H" sub-inspection marks are on the trigger guard and back strap. The left side of the grip has Ainsworth "OWA" cartouche. The bottom of the grip is marked in white ink "274," possibly a collector or museum number. The standard First Model Richards conversion ring and loading gate have the assembly number "181" "181" is repeated on the cylinder, wedge, barrel and back strap and is over stamped the original serial number "122597" on the frame and trigger guard. The nickel plating suggests that the revolver may have been an Indian Police or Scout sidearm.

Fine with arsenal very slightly shortened barrel. Remaining period nickel finish are as followed: 80% on the barrel, 60% on the ejector housing, 50% on the frame and conversion ring, and 75% on the cylinder with the balance a smooth gray patina. Nearly all of the cylinder scene remains. 30% of original silver plating remain on the trigger guard, and traces of original silver plating remain on the back strap. Flashes of original case colors remain on the hammer. The grip is fine with glue repairs visible near the top, high edge wear and minor handling/storage evidence. The cartouche is crisp. Mechanically excellent.