The 2nd gen guns were made of Uberti parts and assembled and finished by Iver Johnson in the USA. They were very well fit and finished, authentic in detail and worth the price.
The Signature Series, on the other hand, assembled by a completely different vendor in Brooklyn NY, were made of parts from various manufacturers. For instance, the 1860 Army I have has a frame clearly made by ASM, if I correctly read the way the grooves were cut on the cylinder base pin. The gun lacks the capping groove, came in the box with a loose cylinder pin, the timing was awful, and the parts polished BEFORE, rather than after assembly, so the corners of the mating surfaces are rounded where they should meet flush, and polished before they were smooth.... I could go on.
I do shoot it (now that it has been cleaned up, tightened and retimed), and shoot my very fine second gen 1860 I as well, and it was correctly done, and needed little touchup tuning out of the box. I have a second gen 1851 Navy that was perfect out of the box, and polished like a black mirror, yet all the corners are square and sharp and all mating surfaces match.