This is a fine example of a rare very early production Colt Double Action revolver that was shipped and sold through the Colt's British agent in London and carries the very desirable full length "London Pall Mall" barrel address and full British proofs as applied by the London proof house. The butt is stamped "91" with an "M" stamped directly beneath it. These 1878 Double Action revolvers were Colt's first attempt in producing a large frame, large caliber double action revolver and although they performed and function exactly as designed they suffered from a weak main spring which sometimes caused failures to fire which gave them a questionable reputation. However, when initially produced they were chambered in the new larger 45 caliber cartridges and were highly sought after by many early western frontiersmen and lawmen to include the likes of "Buffalo Bill" Cody. These pistols were finished with the Colt high polish commercial niter blue finish with the color case hardened hammer and checkered walnut grips. This pistol has been fully proofed by the London proof house and carries the "Crown over the GP" proof for smokeless cartridges along with the secondary proof of the "Crown over V" or view proof. The British proof marks are located on the rear section of each chamber of the cylinder along with the underside of the barrel. The top of the barrel is marked with the single line address of; "COLT'S PT. F.A. MFG. Co HARTFORD CT. U.S.A. DEPOT 14 PALL MALL LONDON". The left side of the trigger guard/bow is marked "45 CAL B", designating the pistol as being chambered in the scarce "45 BOXER" cartridge. It has the standard fixed front sight with a sighting notch on the rear section of the top strap of the frame. These revolvers have a one piece frame with a removable trigger guard/trigger assembly with a single round side plate on the left side that covers the internal mechanism. This revolver has the matching serial number (91) on the rear of the cylinder, the butt of the frame directly in front of the lanyard loop, the underside of the barrel (under the ejector housing), the loading gate and on the side of the frame under the right grip panel. The walnut grips are checkered walnut.