In 1912 Walter Du Brock set up a film company alongside the riding academies he had in Chicago.
Moving Picture World -1912
The family moved to Los Angeles around 1923/4 but seemed to have concentrated on the riding academy rather than movie making.
Walt Disney, big into polo in the 1930's, kept his ponies at Du Brock's stables. He was taught how to play polo by a Du Brock employee Gil Proctor.
sasakitime.com
Ruthie Thompson, who also worked at the stables at the time, went on to have a long successful career at Disney Studios.
I'm guessing that's Walter Du Brock on the left in your picture
e_r ... with maybe his daughter Melba who was also a mainstay of the riding academy.
