It's always fun when you take a chance on a card where the seller doesn't have a scan of the reverse, and then it arrives with a rare back. I won this T205 toughie a couple days ago, no back scan provided. It arrived today and was a P42, which was a nice surprise. Nothing earth-shattering, I know, but a good deal nonetheless.
What's the best "no back scan" surprise you've received in the mail?