Thanks to my cousin Elaine Wilson, we have identified Percy Broder's first wife. She was Kathreen Alice Collier, and like his later wives, she only lasted for a few years before they were divorced. (Either Percy was very unlucky in his choices or he was impossible to live with. I know where I'd put my bet!)
I've added Kathreen's information and made a few updates to Melba (Sigsworth) Pappajohn, Percy's second wife.