Walter Harvey, played by the aforementioned family member of the answer to Q1, was the money and idea behind the AAGPBL in the film. He was based on a son in what family, famous for a baseball team that used to have their spring training games on the island of Catalina from 1920-40.
Wrigley [Harvey was based more on Philip Wrigley than his father, William Jr. who of course owned the Chicago Cubs.]