Rodeo(s) questions

[Original Noah Mercy]

I have a pair of Rodeos in 45 Colt with 4 3/4" barrels. Despite winning one in a drawing back in 2005, and purchasing the other at an auction seven years later, the serial numbers are only 89 digits apart. Both are "D" prefixes with three digits following: D1XX and D2XX. Both have cone hammers, and neither is stamped "Uberti" under the base pin.

Am I correct in believing these are US parts guns, or is there more to it than that?

And how common is it for these to have "oopses" in the serial number stampings? One of them has a number stamped over another, just one digit off, as if they stamped two frames with the same number and then had to correct it.