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. Dickie & Co.