Roll-engraved cylinders were indeed part of Colt's process, a design drawn by a fellow named Waterman Lilly Ormsby
eek:now
there's a handle!). Ormsby was, interestingly enough, a guy who designed bank notes.
The repros will have Ormsby's name also roll-engraved on the copy, as the copy is fairly absolute. There were several different designs, but as previously noted, the majority of these were of a scene in which the Texas Navy beat the sea-going snot outta...erm, I forget...somebody who
lost (snicker).
Walkers & the subsequent Dragoons had scenes of the Texas Rangers fighting the Indians.
There were also scenes of a stagecoach hold-up, I believe these will be found on original Baby Dragoons & early Wells-Fargo models, but the Italian repros pretty much stick to the Navy battle, regardless of pistol type/size.
A few hunting scenes were also done; I'm not certain of this, but I think custom guns were the majority of those roll-engraved with anything other than the Naval battle. When Colt began converting their black powder revolvers in the late 60's they retained the roll-engraving, primarily because they had a plethora of parts they needed to move & there was no point in making new cylinders when those on hand were just fine for the conversion.
I'm unsure how to copy images from the net & paste them to a post, but a search for
Colt roll engraving brought me a number of sites wherein these can be viewed & there are a number of books that depict much of what I've said, albeit with far more accuracy than my memory allows. Dennis Adler & RL Wilson being the two I am familiar with; their books are easy to find & somewhat easy to afford, though Wilsons' books become rather high-dollar once they are out of print (I recently picked up a book of his called The Paterson Colt Book: only 3,000 were printed, all signed & numbered; I got mine still wrapped in original plastic for $45, shipped...which astonished me, as the book has a $125 price printed on the inside of the jacket).