Talking of X-Men, I spotted this copy on eBay last week and made a reasonable offer which the owner unfortunately declined. Shame, as I'd like to have studied it more closely in hand. It seems to be a UK copy with the price missing from the cover. I can't say for certain that it hasn't been removed somehow, but the absence of the T&P indicia is a second clue that the omissions are genuine production errors.
It's a cool book, which I would have bought without a second thought back in my misprint collecting days, but I can't justify the asking price anymore and will just have to be satisfied that it appears to exist.
This is what the indicia should look like by the way: