I like the coin and think it is a proof as well, I will be really interested to see more photos and see what you decide to do and how it comes back...
Usually they only have Heritage auction books and State Quarter Folders, but once in a while something comes through. Got a Overton Early Half Dollar Die Varieties book there a while back too.
Try online. There are at least four copies of the Breen book on proofs in the $35 to $45 range (and others at higher prices).