In "Your Job in Germany", at approximately 1:22, Hitler, who was standing behind a podium giving a speech, fades into blackness, but the podium itself remains.
IMDB credits Adolf Hitler as himself, which, if correct, would rule out filming with an actor, and then filming without the actor, and fading from one to the other.
Given that it was made in 1945, how did they achieve this?
The film has some other fading out of items immediately subsequent to it, but none of them seem as hard to achieve as Hitler disappearing.