I just put up a new post about the 1981 San Diego Union "Meet the Padres" set after someone mentioned it on FCB:
1981 San Diego Union - Meet the Padres
I'd also done a rather sloppy post a few years ago about newspaper "cards" in general and tried to list as many sets for which I could location information:
Baseball "cards" in Newspapers
I still update the post when I find new information.
I suspect the "Sports Stamps" from 1936 only ran in Hearst owned newspapers, but I don't have access to an archive of any of them for 1936 to work on a checklist. I'm not sure if the player selection was regional, or if the same stamps ran in all the newspapers that carried them.