One film I could find was "The Plot to Overthrow FDR (Smedley D. Butler)" at
www.ihffilm.com/r547.html
And the rare and expensive book by Jules Archer "The Plot to Seize the White House"
At around $300 a pop, it looks like they don't want us reading or hearing about Prescott Bush and George Herbert Walker's involvement in this plot.
The Bonus Army made all of this happen. That book on CSpan
The Bonus Army: An American Epic
Paul Dickson and Thomas Allen
http://www.booktv.org/history/index.asp?segid=5515&schedID=336showed that the Army was scared $%*@-less of their own vets asking for what was rightfully theirs; plus a shot at making it to the middle class, which the post-WWII vets got with the GI Bill. And the authors show Army intel was doing domestic operations and agent provacatuer stuff too, which gagged me, much as the MLK stuff from the 70's did in fast forward...are they doing it today ??