Good catch Trey.
It seems that Old Cardboard has listed the R310 subjects found with the red overprint display ads, and they are:
Bartell, Berger, Boyle, Carleton, Chapman, (Rip) Collins, Derringer, Earnshaw, Frey, Frisch, Gehrig, Grabowski, Moore, O’Farrell, Ott, Spohrer, and Swetonic. Five of these are St. Louis Cardinals.
This looks to be consistent with my memory (Carleton and O’Farrell are among the most common if I recall correctly), although I can check old records for more. Please feel free to post scans of these or any others. Again, note that none of the 17 that carry this ad can be found in the Canadian version, with the possible exception of Lou Gehrig if confirmed. It will be interesting to see if anyone can show a Ducky Medwick or Rogers Hornsby example with red ad overprint, as they are two more Cardinals who do not appear in the Canadian version.
As for the base set, it is also heavy on players who appeared for the Cardinals in either 1933 or 1934 and, upon a cursory review, it appears that not a single Chicago Cub is represented. That is curious, given Curtiss/Butterfinger was produced in Chicago and the Cubs at the time had four HOFers along with ace Lon Warneke.
Anyway, here is another of my faves:
