The 1921 E121 cards are found with a variety of different back advertisements some more difficult to obtain than others. The most difficult however are the cards advertising the Herpolsheimer's Boys Fashion Shop. The reason for this is that until late 2018 just 69 or 70 cards from the issue are known to exist no more than one example of each subject. The cards were all discovered together in late 2004 auctioned individually on eBay and had been previously unknown to the hobby. Such a discovery is an earth-shattering piece of news for sure and the demand for the cards was strong among advanced collectors. Each of the cards auctioned were in EX to EX-MT condition with one exception: each and every card had a dollar figure notated in pencil on the reverse. The purpose of these notations is unknown: perhaps they were dollar figures used by the Herpolsheimer's clothing store in Grand Rapids Michigan as some sort of coupon redemption. Perhaps they were the price the cards were sold for to the original eBay seller in some flea market or garage sale. There is unfortunately no way to know. What we do know is that there is only one example of each subject in the E121 Herpolsheimer's set meaning each card was one of a kind. Proving the adage that nothing is one-of-a-kind however a grouping of Herpolsheimer cards were discovered in 2018 by a collector who presented them to the Net54 message board. While the checklist of cards in that find is currently unknown we do know that they were not one-of-a-kind and may have actually been commercially distributed. This example featuring Hall of Famer Ray Schalk is graded GOOD 2 by SGC due to the pencil markings on the reverse but obviously has the appearance of a much higher-grade card. Quite rare since the cards from that find have yet to be graded or identified the Schalk is at worst one of two examples known and quite possibly still the only one.