I can remember back in the late 70's there was really only the MS60; MS63; MS65, and MS67 grades for uncirculated coins. Commercial Unc; Choice Unc. Gem and Superb Gem. (I remember something about a grade of 'Select Unc' but that may have been to describ
Gilboy uses a rarity scale that is somewhat similar to the Judd US Pattern scale for those who are familiar with that book. (It might not be his but that is where I have seen it in my copy.) The difference between his scale though and Judd’s is that he uses a more confusing set ...