This variation was called the "Type 7 - New Model Breech Loading Police Pistol" in "Variations of Colt's New Model Police and Pocket Breech Loading Pistols" by Breslin, Pirie, and Price. These were manufactured in relatively limited numbers in 1873-1875. It has a post front sight, two-line Hartford barrel address, an ejector on the right side, the 1871 and 1872 patent dates on the frame, rebated non-fluted cylinder, "36 CAL" on the left side of the trigger guard, and a loading gate. The visible serial numbers all match and several have "L" by them suggesting this gun was meant for Colt's London agency, but it lacks London proofs indicating it never made it to London.