I bought a reproduction of the Colt 1860 Army, marketed by Traditions, a couple of years ago. It was made by Pietta.
The Colt 2nd and 3rd generation cap and ball revolvers were made from raw parts supplied by Uberti, to Colt's specifications. My 2nd generation 1851 Navy is exceptionally well made and finished.
My understanding of the Colt/Uberti connection goes like this:
Colt wanted to start remaking its cap and ball sixguns back in the 1960s but realized the enormous tooling involved. Colt approached Uberti about having the guns made by the Italian maker, to Colt's specifications.
Uberti said it could, but Italian proofing laws required that every finished gun made in Italy be proofed in that country, and bear an Italian proof mark.
Colt knew that this Italian proofmark wouldn't set well with American shooters, so it compromised. It had the raw castings and forgings for the major parts (frame and barrel assembly) made in Italy, then shipped to the U.S. for machining and finishing.
Smaller parts were made here, either by Colt or subcontractors. I seem to recall that Iver Johnson was a subcontractor at one time.
Anyway, the guns were machined and proofed here in the U.S., avoiding the troublesome Italian proofmark.
Some shooters get their dander up and proclaim that such revolvers are not Colts, but Italian-made. I take issue with this because only the steel and the raw forging or casting is Italian.
Is an American-made gun that uses steel from Germany or Sweden not American, then? What about all those extremely well made Winchester and Browning rifles made by Miroku in Japan?
And, of course, there's the Brownings made in Liege, Belgium. I've never seen anyone get all uppity about a Belgian-made Browning, dismissing it as not made in America.
I'm very pleased with my Colt 2nd generation and my Pietta-made copy of the Colt. My Uberti-made copy of the Remington .44 is very well made.
Frankly, I can't understand why Remington hasn't reintroduced its cap and ball or cartridge revolvers. Smith & Wesson reintroduced the Schofield; Remington could make a killing on the market. Many of us would pay extra money to have Remington marks on the frame and barrel, just as the Colt displays.
As for ranking by quality, I've long heard that Uberti is the best of the foreign-made revolvers available in this country (a couple of German firms make cap and balls, I'm told, but they're not imported by the U.S.).
However, recent reports on various websites indicate that Uberti quality has slipped, while Pietta quality --- once average --- has raised considerably.
My Pietta-made Colt 1860 Army is very finely finished and made. I had to remove a couple of tiny burrs in the action with a needle file, but that's normal with any cap and ball today --- including Uberti.
Quality of Piettas seems to range wider than that of Uberti, however.
Armi San Marcos is of average or poor quality. I have an ASM copy of the 1862 Colt Police that required a little smoothing and shoots okay, but its finish is rough --- tool marks abound.
From what I hear, the finest you can get is the Colt 2nd generation, in whatever model. My own 1851 Navy bears this out.
The bottom line: Look over your revolver before buying. If you order it by mail, don't be afraid to send it back until you get one that is decent quality. And if you get a rough-hewn clunker each time, get your money back and save up for a higher-quality gun.