The PRC hub has been attributed to the Piping Rock Club in Saratoga Springs, NY for years. Peter J. Sullivan has been placed running several illegals in Saratoga Springs. I'm from KY - Show me!!!

Peter J. Sullivan
Elite Club
French Lick, IN
March 29, 1937
Green $25-Brown $5-yellow no denomination.
Notation on the card says-"Formerly at the Piping Rock Club-Saratoga Springs, NY." I take this to mean Sullivan.
Very possible the chips found their way to SS. Peter Sanders has some information. Hope he will post it.