This great seller is correct - this is one of a complete set of four mechanical nut cups that I know are exceedingly rare. Beistle issued the set for one season only in 1938. They slightly adapted already existing artwork to produce the set. (So many firms were hurting then due to the lingering Great Depression that cost reductions were more important than ever. Beistle wasn't immune, hence this set.) I had the good fortune of buying several complete and unused sets and then several singles out of an estate in Massachusetts in April 2015. I kept the best one, auctioned the next best one for ~$1800 and sold everything else over the next few years. (I am never in a hurry to sell anything.) Beistle printed these on surprisingly thin paper stock considering their intended use. Few survived unscathed. Few exist overall - so when an opportunity presents itself to get one, especially from such a wonderful seller, don't let it slip by.
06/14 Update: This sold for a modest $119.50.