Doc,
I've got one of them. It has the flip-up, ladder style adjustable rear sight and a drift front sight. The brass skeleton stock is nickel plated with a brushed finish. It is a copy of the original 1880's Colt "Special."
Colt reissued a very limited number of them a few years back but the USFA gun is actually a bit more true to the original than the Colt. The original had a small, round vent hole in the top-strap of the frame, right above where gap is between front of the cylinder and the breach (forcing cone) of the barrel. It was supposed to eliminate fowling. It didn't. Colt omitted this detail from their reproduction, USFA included it.
It would be interesting to know how many of these guns were made by USFA. It is a rather unique variation of the SAA but I doubt if there was a lot of demand for them.
CJF