Verify the attribute

There is a Flowing Hair Dollar on eBay that is slabbed NGC BB-20 . I looked up the die marriage by picture in Reiver's book and I come up with the fact that he has it designated B-2 (his numbering) and it is only a Rarity 1. The ebay auction intimates relative scarcity ( which the NGC designation is!). Can someone verify the attribute for me. I have only one book and am inexperienced in this field. Is BB-20 (Bowers & Borckardt) the same as Reiver's B-2. Thanks.
1795 Flowing Hair
1795 Flowing Hair
Wondo
0
Comments
Dave
Thanks, Dave. Any others?
Can anyone attribute this and give me the relative scarcity to the other varieties please?
ttt - last time I promise!
Hope that's what you wanted.
Thank you. That's exactly what I am looking for. It was kinda neat to see a coin and be able to attribute it to the proper variety. I hope I don't strain a muscle patting myself on the back!
Thanks again!!
The real point is that even though NGC has attributed very few, this type should not get a variety premium if we are correct!