If you'd like to purchase the documentary, you can find it on the Smithsonian Folkways DVD titled White House Workers: Traditions and Memories. Click HERE to buy. It's $15 a copy.
I'm surprised that they aren't fully exploiting the release of Lee Daniels' film and re-releasing their documentary, maybe on blu-ray, or even VOD, with a new campaign, touting it as must-see footage of the real butler, and charging $30 for it!
Below you'll find 3 clips from the documentary, featuring Eugene Allen talking about his career, as well as recalling moments with Presidents Carter and Reagan.