The side hammer on the #3 revolver caused the recall button in my head to recall reading about Elisha Root who was a childhood friend of Sam Colt, later to be his factory superintendent, co-designer, and later to be Colt President after the death of Sam Colt. Reading in books by Haven, Wilson, and Alder, they write of the series of side hammer percussion revolvers designed by Root. The only ones ever produced in the mid to late 1850's were referred to "Pocket Pistols", which were five shot calibered in .31 and .265 (called a 28 caliber in one reading). They are of the ones always pictured with the side hammer, top strap, and no trigger guard normally seen on Colt revolvers. According to writings I've read, Colt and Root did make some experimental 'Root' designed percussion prototype revolvers (side hammers, top straps, and trigger guards) that were of 36 and 44 caliber that had larger frames than the other Root designed production revolvers. They were never put into production as Sam Colt thought the guns were to heavy, complicated, and clumsy. It is written Colt didn't think they would sell well. In the books I have there are pictures of several of the 'experimental' large frame Root designed revolvers, all in private collections and/or museums. More than likely the one you saw and pictured Long John is one of the 'experimental' ones that somehow escaped from the Colt factory. Your picture looks like the photo's of the one's in my books. Just speculatin'. Someone probably has more info than I've typed here, but this is what I've read by the authors I named. Nice lookin revolvers in your pictures. Be interesting to handle the side hammer one.