"Odd Stuff" indeed! We can only speculate.
When Colt took USPFA to task over their us of the word "patent" in their name (back sometime around 1994) they had to change their name to USFA. There was, no doubt, an amount of inventory marked USPFA that USFA could not sell as such. A couple of years later USFA introduced the Rodeo. Highly probable that some of those early USPFA guns were still in stock and were refinished and re-barreled (to replace the USPFA roll marks with USFA marked barrels) in order to make some sort of profit from the unsaleable stock they still held in inventory.
When the Rodeo was introduced it "sold like hotcakes," as the old saying goes. In the rush to fulfill orders it is possible that a few (or maybe more) might have slipped by without barrel markings. Just a guess on my part but, being a big fan of USFA, and knowing the history of the company, I can't dispute Yahoody's fact that there was a period, during the late 1990's, when "odd Stuff" was not all that odd. The transition period from Italian import to all US made guns only added to our confusion. Is your gun (1) Italian made? Is it a (2) mixture of Italian and US parts? Is it (3) all US made?
No doubt about it, USFA turned out a very fine SAA revolver no matter what "stage" the were in (lets face it, that's why we are here together on this forum). It is unfortunate that the previously mentioned "3 questions" will forever be asked.
Bottom line for all three... if it shoots well, who gives a damn!