I am not much of a Browning collector but went through a collection with a few 1837 and curious if anybody has a solid set of diagnostics to attribute the very rare B-7? I know small arrowheads but are they super, super tiny?
I think you mean B-6 because there isn't a B-7 (or at least I haven't heard of it yet). According to the Steve Tompkins book, it appears that B-1 (R.3) and B-6 (R.8) share the same obverse die. On this die the 3 in 1837 is lower than the other digits, the 7 is further left than the die used for B-2 and B-3, and the date is more widely spaced than the die used for B-4 and B-5. For the reverse, the top arrowhead is especially narrow. When comparing B-1 and B-6, the 2 in 25C. is beneath the feather on the arrow for B-6 but not for B-1. Below are links to pictures of B-1 and B-6. B-1: https://www.ngccoin.com/coin-varieties/draped-bust-and-capped-bust-quarters/1837-25c-b-1-5240/ B-6: https://www.ngccoin.com/coin-varieties/draped-bust-and-capped-bust-quarters/1837-25c-b-6-2162/ Feel free to post pictures of the coins in question!
Yep, it's the 1837 B-6 you're talking about. Last I heard there are only three known. Heritage (I think) auctioned off one a couple months ago. You should see a good image there. I stretched my numismatic budget but got outbid. It's the only one I'm missing.