Someone's in for a rude awakening.
He's misidentified it, as the design is that of #WS6, not WS5, but... the impression is wrong, the perfs don't look right, and this stamp was only issued on green paper, not white paper.
Listing text states "i have had this put away fo years , purchased from a stamp show here in Florida!"
I disbelieve, but I've contacted the seller. We'll see what he says.
https://www.ebay.com/itm/US-WS5-5-W...133082091911