I would politely disagree about the E97 Black and Whites being proofs. To me, they don't have characteristics of a proof as I normally think of what a proof is.
There are many copies of each (still very scarce though), the names are on them and they generally don't have cross hairs for alignment. My guess is they are a completely separate set. And as to why their condition is usually not very good, I think we can look at all paper thin series and tell from their stock that they didn't hold up well over time. Just a few thoughts....and I could be wrong
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