I used to goto the internet archive and find a lot of really old stuff. Have not been there in a long time but its got a huge selection of old stuff also a huge selection of government anouncement public education type stuff From way back.
Wherever you look, try to find some of the old Disney Nazi films... They're fucking classic. I picked up the DVD set back when they had them on the shelves - great fucking stuff. In fact, Disney shut down it's whole studios to make war propaganda films for WW2... Shit you'd never see in today's world...