I was only able to find one reference to a "bacon" gun. They were a commercially produced gun, some attempts were made to sell them to the military during the Civil War, which failed. Apparantly they had some kind of legal fight with Smith & Wesson later, and went to making "derringer" type handguns.
My book, "Guns of the Wild West; Firearms of the American Frontier 1849-1917", has a photograph of a Bacon revolver that looks exactly like yours (except it's in focus and B&W).
They were apparantly a competitor to Colt, but I have no information on how rare they were. As stated, Smith and Wesson sued Bacon (and a number of other New England companies) for infringing Rollin Wite's patent allowing bored-through cylinders, as Bacon was also making .22 & .32 cartridge guns.
The gun itself seems to be patterned after some of Colt's smaller revolver (the cylinder looks like a 1862 police, for example). Other companies made copies of Colts, such as Manhatten Revolver Company.
Sorry I couldn't be more informative.
