Hal:
I said I was not sure about the cylinder; couldn't have stated that more clearly. I could probably tell if I could actually see it. As for matching numbers, I have seen many, many Colts and replaced Colt parts which have been numbered to match. I am confident the barrels - both of them - are mid to late 1960's or newer. I saw the photos you posted under the "old things" thread and the barrel caliber markings on both barrels are late 1960's or newer.
I started collecting single actions about 1971. I have owned at least a hundred of them - 1st, 2nd and 3rd generations; mostly 1sts. I am a life member and been active in the Colt Collectors Association for over 20 years, having recently finished serving on the board and as treasurer for eight years. None of that makes me a "Colt single action expert", but I might know more about single action originality than a local gunsmith who screwed a barrel back into a frame and indexed it.
While I'm at it, I may as well tell you, for a gun made in 1880 your frame is wrong also. Your cylinder base pin is retained by a transverse screw, nut and spring. That method of retention didn't appear on Colt single actions until around serial number 165XXX, or about 1896-7. And it did not become common until about serial number 167000. An 1880 Colt would have the base pin held in place by an in-line screw coming up through the front of the frame below the barrel, upward at about a 45-degree angle. The tip of that screw itself extends into the groove in the base pin and holds it in place.