Donald Woods appears as the character Carl Montaine. In 1937, he would actually play Perry Mason in The Case of the Stuttering Bishop, the last in the Warner Bros. Perry Mason series.
In The Case of the Curious Bride, one of Errol Flynn's earliest films, his role consisted of lying on a marble slab as a corpse. There was also a flashback sequence towards the end of the film showing how Flynn was killed. The film in question has appeared at least twice on Turner Classic Movies during Errol Flynn festivals despite his very limited (certainly less than two minutes) screen time.
Unlike the novels and the Raymond Burr TV series, which used Los Angeles as a location and/or base, here Perry Mason's offices are in San Francisco.