Jeff
There was a letter the Spalding co sent out to players they wanted in the set, and the letter mentioned an example included with the letter of what the set would look like. I always assumed the example mentioned was the Grange card. The date of the letter was April of 1926.
That stip card is ugly, so I hope that's not it.
SPC I read might have been 1926?
Excellent article by the way, I read it front to back