
Just for Fred then:
The actress born as Diane Hall, and known to her friends as "Annie", changed her surname to Keaton (her mother's maiden name) early in her acting career to avoid confusion with another Diane Hall.
Also interesting (to me at least): Michael Keaton was born Michael Douglas, but borrowed Diane Keaton's assumed surname to avoid confusion with the Michael Douglas, son of Kirk Douglas. Although that other Michael apparently was really born with his name, his father was born Issur Danielovitch and changed it to avoid confusion as a guy with a funny ethnic name. (Times were different then.)
Here are some real names from Hollywood's Golden Age. What are their stage names?
Marion MorrisonArchibald LeachBernard SchwartzNorma Jeane Baker (or possibly Mortenson)
Now I'm tapped out. I'll shut up and let the
thread die ... unless anyone else want to contribute!