The last several nights, I've been going through the smaller of the two bulk lots I got at CHICAGOPEX, pulling items to sell to a collector who plates various 1st issue revenues. I didn't find anything spectacular, just a few silk papers and a few very minor double transfers.
I finished up with that lot and tonight I started on the big lot. Throughout the entire 12 volumes are various and sundry stamps turned face down with pencil notations on the back. I really didn't pay any attention to them when evaluating the lot, nor did the seller.
The very first page I start working on, R53c, had the following stamp face down.

I was expecting one of the R53 double transfers with doubling of the letters in the top scroll. Instead I was greeted by the following stamp. Listed but unvalued in Scott.
Hard to imagine an identified item like this just stuck in a bulk stockbook. Makes me think I'm going to have to take my time and pay very close attention as I go through the rest of the lot...
