I am seeing copies of the Abrams/Dorst puzzle book "S." advertised for sale as "first edition, first printing." Since the edition statement is inside the back cover of the slipcased book, which is closed with a paper seal (in addition to being shrink-wrapped), how can you tell?

I was in Barnes & Noble today with a $25 gift card, and I'd have bought the book if I could have been sure I was getting a first printing. I did not see any indication on the outside, and would appreciate a tip-off if anyone has it.