This is an exceptional example of a London proofed Colt Model 1855 Sidehammer revolver with correct case and accessories manufactured c. 1863. This Model 5 revolver has a 3 1/2 inch, .31 caliber, round barrel, five-shot fluted cylinder with non-removable percussion nipples, round loading lever with octagon base and cylinder pin latch and retaining screw on the left side of the frame. The barrel is roll-stamped: "ADDRESS COL. COLT/NEW YORK U.S.A." in two lines. "PATENTED SEPT. 10th 1850", is roll-stamped in one cylinder flute. "31 CAL." is roll-stamped on the right side of the frame behind the capping cut-out. London "Crown/V" and "Crown/CP" proof and inspection marks are stamped on the left side of the frame and on each cylinder chamber. The serial number, "7148L" is stamped on the butt and "7148" is stamped on the underside of the barrel. The "L" following the serial number indicates a gun produced for Colt's London Agency. The barrel, frame, and cylinder have the Colt high polish commercial blue finish and the trigger and screws are a fiery niter blue. The loading lever and hammer are color casehardened. The one-piece walnut grip has a varnished piano finish. The revolver has a British oak case with brass reinforcing screws and round brass inlay on the lid. The case interior has six compartments with a dark green baize lining. A Colt instruction label is glued to the inside of the lid. The case contains: (1) 500 count tin of Eley percussion caps for Colt's belt and pocket pistols with dark green label, (2) steel cleaning rod with turned maple handle, (3) five round packet of Hazard's combustible cartridges for Colt's or Whitney's .31 caliber revolving pocket pistols, (4) L-shaped combination screwdriver for Model 1855 pistols, (5) iron, duel cavity, bow-leg, .31 caliber, bullet mold marked "COLT'S PATENT/II" on the spruce cutter, (6) bag-shaped Dixon powder flask with adjustable charger and lanyard ring marked: "COLTS POCKET FLASK" on the lid (7) "Dixon" marked pewter oil bottle, (8) key and (9) .31 caliber cartridge and assorted .31 caliber round balls and conical bullets.