I have this 1875-CC quarter in PCGS 58. After further research, I find that it is an obverse die that is not in Briggs' book. It is paired with reverse A. After you know what you look for it is easier to tell from obverse 2 but they are very close. Here is a photo of my "3A". If there is much interest for doing your own research, I'll tell ya where to find higher resolution photos of another one that I could only wish I owned... From my initial study with my meager means, research, and abilities, I would say that the "3A" is about three times scarcer than the "1A". I am of course interested in what you experts have to say and I think I can easily defend my argument for a third die paring with an unknown obverse die.