I got one of the Saturday Evening Post cards recently as well. Seems like there are a few names that were stamped with SEP agents.
I have also seen some T206s lately that have the following on the back:
"May 31" Nap Lajoie
"Howard W Dulance" spelling on last name? Oberlin
"William Stratff" Schulte
"BL White" Clancy
"Special" Mattern
If anyone is looking for these, let me know and I'll point them out to you on the web.