This is going to be a little vague, but perhaps you can use it:
 
Anthony Slide, the film scholar, wrote a book on the subject of the history
of vaudeville. As Slide is an Englishman and his primary field is film, it
might be of some use to you. Sadly, I do not recall the title. Slide can
probably be reached through the UCLA Film Archives in Los Angeles.
Gene Stavis, School of Visual Arts - NYC