In 2008, California State University, Northridge produced an exhibition:

In our Own Backyard: Resisting Nazi Propaganda in Southern California, 1933-1945

[n.b. The exvibition documents are no longer online at Northridge, but have been preserved in the Internet archive]

This exhibition has a couple of images of him, as well as a number of documents relating to his activities with the America First and the Friend of Progress organizations and the sedition trial.