What is a preferred source for Rarity Numbers? I was working with my US Half Cent set fleshing out my Excel database. The Greysheet has a 1809 Classic Head (C-1) labeled as a Rarity 7. But Fuhrman's Handbook calls it a Rarity 4. That's too big a spread. The catalog values I can find for that coin makes me reasonably sure the the R-4 value is much closer to the truth.
I once owned an example of that 1809 half cent variety. It was a fairly recent (the last 45 years discovery), which has minor differences from the other 1809 half cent varieties. As I remember it, it resembles the “6 over 9” variety. As more owners check out their coins, chances are more pieces will be discovered, unless it’s a real rarity. The R-4 rarity rating is correct. A lot of the discovery pieces are probably low grade or they have problems.