This is a Hartford London Colt 1851 Navy, manufactured somewhere around 1866.  Although manufactured at Hartford, Connecticut, it was made for sale in England.  The barrel address is "Address Col Colt London."  It has English view and proof marks on the barrel and cylinder and a tiny L beneath the serial number on the barrel, frame and trigger guard.   The gun has matching serial numbers with a considerable amount of blue on the barrel and fading case colors on the loading lever, frame and hammer.  It is extremely pleasant looking.  The case is authentic, of the period and at first struck me a little odd.  Even though it is made of oak, the interior is lined with the maroon velvet like a Hartford case of the period and it has a Hartford butterfly in the lid.  Beyond that, there is a Colt label on the inside of the lid, not an English dealer label.  While the flask is not the normal flask you expect to see, the case was originally laid out for it.  The earlier cased Colts that were cased in London almost always have a Dixon flask.  This flask looks to be American made.  I finally figured it out.  The reason this case looks a little odd and has so many Hartford characteristics about it is that not only was the gun made in Hartford for the English market but the case was as well.  Price $9,750.  Price Reduced $8,250!!