We are gratified to learn of the existence of Dave Mallen, not to be confused with Dave Madden or Dave Chasen. We don’t know tons, but what we know, we share. Mallen started out in burlesque. It was noticed that he bore a strong resemblance to George M. Cohan, so he was hired by Cohan’s reps to be his official understudy for about a dozen years. Both Joe Laurie and the Sobels mention him in this context in their respective vaudeville books. He was said to be the best Cohan impressionist in a field that had many, and essentially did his take on Cohan for 40 years. Cohan reportedly said that he did Cohan better than he did himself!
Mallen was a staple in vaudeville throughout the ’20s, and then went back to Broadway, this time in his own right. As such he was in Padlocks of 1927 with Texas Guinan, George Raft, Lillian Roth, Jans and Whalen, et al; Arrest That Woman (1936) with Gertrude Short and Hugh Marlowe; The Show is On (1937) with Willie and Eugene Howard; Censored (1938) with Percy KIlbride, Marion Shockley, and others; Ringside Seat (1938), and the 1951 revival of Oklahoma!
The Billy Rose division of the NYPL has his papers; access them here.
For more on vaudeville history, please see No Applause, Just Throw Money: The Book That Made Vaudeville Famous.