He developed Electrical Porcelain with transmission engineers at GE. His family continued to work at Building 68 in Schenectady for decades. William's son Frank Cermak advanced insulator design into the mid 20th century.
When Rex Harrison accepted his Academy Award for My Fair Lady (1964), he dedicated it to his two fair ladies, Audrey Hepburn and Julie Andrews both who had played Eliza Doolittle with him.
Some doubling was employed in the minor parts. MY FAIR LADY played for 2,717 performances on Broadway at the Mark Hellinger, Broadhurst and Broadway Theatres starring Rex Harrison, Julie Andrews, Stanley Holloway and Robert Coote.