This is a beautiful example of a Colt 1851 Conversion Revolver in .38 Rimfire with 7-1/2" barrel, blued/case colored finish, and walnut grips. What makes it truly unique is its Colt London Navy conversion...and appears to be a late London production '51 that never sold and was eventually sent back to America. We cannot find any other examples of London Colts with conversions and could be one of a kind as there are no references in any books...including Flayderman's guide or the Study of Colt Conversions by Bruce McDowell. The serial number is in the 42,000 range which puts it as one of the last London Navies produced. Most books say that the last London Colt was serial number 42,000...this one is 42,011.
In terms of aesthetics, this Colt is what collecting is ALL ABOUT! It has a look that's hard to characterize its qualities in terms of condition, percentages of finish, numbers, or even words. High condition but has been left untouched. If your eyes could talk, they'd probably say something like, "this is nice enough that you know exactly what it would have looked like back when it was new...yet, I can still tell it's over 150 years old. Some collectors might call this "condition with character wear". There are probably many definitions...but for me personally, this is art in the form of craftsmanship fermented by time and mother nature. It's funny how many of us who collect can universally pick a gun like this out of a crowd regardless the number of years we've collected, what we think we know, the number of books we've read, etc., or how old we are...it just stands out.
Originally, this Colt started its life as a Model 1851 Navy Percussion revolver in the London Factory but went back to Colt in Hartford for conversion to the .38 rimfire cartridge during the early to mid-1870's. According to the experts, there are basically three types or groups of the 1851 Navy Richards-Mason Conversion revolver. The first type are guns Colt made from NOS parts left over from the original 1851 manufacture which ended in 1873. These guns were serial numbered in their own range from 1 up to 3,800. The second group of guns converted were existing 1851 Percussion revolvers sent back to Colt by the US Navy. The Navy tended to purchase their weapons in blocks of serial numbers. Most "Navy Navy" conversions fall within 55-63,000 and 89-91,000 serial ranges. The third group were existing 1851 Navies that were either sent back to the factory for conversions or guns that Colt never sold. That is where this revolver fits in but every book I own references these as American-made Navies. A London Navy with a Richards Mason Conversion falls into a special subset that appears to be undocumented. If any one out there has info on these, please let us know so we can make a new reference.
Overall condition grades to NRA Antique Fine++ to Excelllent. The frame retains a solid 80% of its original case colors which are still bright and healthy looking. The barrel has 75-80% discernable original blue that's beginning to fade and tone to brown. Ejector housing shows 40-50% blue with a little bit of roughness. Cylinder...which is often the most worn component on an old Colt still retains 70% original blue that's thinning and toning to brown. Hammer shows 50% darkened case colors with original firing pin intact. The iron grip straps have mostly turned to brown patina with original blue still showing well on the profiles and in protected areas. The grips are original and remain in fantastic shape, still orange hued that's never darkened with 90% original varnish. Perfect metal fit. Very solid with no cracks, repairs, or significant chips beyond the size of a pin head. Mechanically, the action functions flawlessly with the barrel still tight to the frame. Bore is Excellent...still bright overall with a little bit of frosting. The rifling is still deep and pronounced with no signs of abuse, rings, bulges, serious corrosion, etc. Not saying there aren't better ones out there, but for a 150+ year old black powder gun, you'd be hard-pressed to one with a better bore. All in all, just a great looking Colt with tremendous "eye appeal".