Ronald Colman - actor (Lost Horizon)
C.L. Langley - owned a chain of theaters on west coast
Henry Henigson - producer (worked with Carl Laemmle, Jr.)
There are many Marco Hellmans - The Hellman family was one of the founding LA families - my guess would be this one was the musician and song writer (wrote for Duke Ellington among others)
John B. Leonis founded Vernon, California
John W. Considine, Jr. - writer, director, producer (Boys Town), father of Tim Considine
Edward Small, another film producer (The Count of Monte Cristo)
Carli Elinor - fascinating man: began playing violin with film house orchestras and moved on to Los Angeles in the 1920s. He served as concert conductor at the Miller, Loews State, Egyptian and Carthay Theatres. Elinor was one of the first composers to introduce sound effects in films, and is said to have written over 1000 motion picture film scores.
Mary Sinclair Crawford - about the only woman on the list, so who was she? Not sure when, but at one time she was a leading lady in Women's Rights, and Dean of Women at University of Southern California.

Gotta be more, but that's all for tonight.