Manufactured in 1883. The barrel has the scarce "COLT'S PT. F.A. MFG Co HARTFORD CT. U.S.A. DEPOT 14 PALL MALL LONDON" address and is chambered in .455 Eley. The trigger guard is marked "455 CAL/E." Only 1,147 Model 1878s were manufactured in .455 Eley with a 5 1/2 inch barrel and blue finish per Don Wilkerson in "Colt's Double-Action Revolver" (pg. 359). London proofs are stamped on the underside of the barrel and behind each cylinder flute. The cylinder and both grip panels are numbered to the gun. The partitioned case features a Colt London paper label on the interior of the lid and contains an added cartridge block holding 28 rounds of .455 Eley, case key, oiler, cleaning rod, and combination tool.