1959 Topps Salesman Sample question

[divot]

I own a Topps 1960 panel with Dutch Dotterer, Ruben Gomez, and Rocky Bridges on the front and Jerry Lynch on the back behind Bridges. The usual "sales pitch" is written behind Dotterer and Gomez. I obtained the panel from the owner of a small grocery in Tennessee when I was a boy; I have had it ever since. (I also own a complete 1960 NM-class Topps set, which I have upgraded in recent years to improve centering and other issues). Although I have seen numerous examples of the 1960 8-card Salesman Sample and other 3-card panels, I have not come across another example of the "Dotterer, Gomez, Bridges" version. Can anyone shed any light on whether he/she has encountered this particular version and upon its relative scarcity or abundance?

I am having trouble scanning the panel (I'm new to Net54. The front and back of the panel are scanned into my computer in pdf format, but I cannot make the Net54 system upload the photos). Owning thousands of cards and being an active buyer over the past decade, I'm just about certain that my panel is EX+ or so. Although I have kept it in pretty good shape over the years, it has slight wear on one corner.