Posted By:
Jason CarotaThanks for your responses, Jerry and Andy.
I was aware of the D327 set and it's correlation with the E121 set and others. However, I believe I was confused by the SGC flip on the card I won. For reference, here is the scan:

The flip says 1921 E121, so am I correct in saying that it would be one in the same if the flip said 1921 D327? Could an M101-4 Morehouse Baking card instead be listed as a D352?
I've only been in the prewar area for a little over a year, so I am still trying to piece all of this info together.