Possibly from one of Comiskey's famous hunting trips before he and Johnson became crossways.
Leland's had an auction of a signed RPPC of a group of execs on one of those trips, but they are only showing the signed back of it now …maybe you can find the front for comparison or use this list of names as a starting point to look through
https://lelands.com/bids/comiskey-jo...d-postcard-psa