.31 Iron mould with sprue cutter, for Colt Model 1849 London Pocket percussion revolver. Straight leg mould, stamped “COLT’S PATENT” with an apostrophe, on the top face of the sprue-cutter, close to the hinge. The two cavities are for a round ball nearest the hinge pin and a conical with a heel grease groove below it. The groove helps facilitate loading into the cylinder chamber. The locating pin is on the left leg. The width and the depth of the mould is smaller than the American made mould for the Colt Model 1849 Pocket. The finish is blue.