Well that’s one mystery solved!
Sometimes fate cooperates; the timing on this is wonderful though. I picked up the following document at CHICAGOPEX, primarily because it looked like a potentially interesting cancel design that I might be able to pull out of the image. When I ran the cancel through Retroreveal, lo and behold a familar design appeared: Less than a month ago I picked up a gorgeous example of this cancel, but had been unable to determine its origin. Well, mystery solved: E. P….