The 1943 Batman Serials
I just saw the first disc, of the two-disc Batman serials of the forties (see info on Wikipedia). This disc was the first-disc of the two-disc 1943 serials. I haven't seen the second disc yet.
Also, there was a second serial in 1949, and I read the budget on this one was even less than the first, so I'm not expecting a lot.
One thing about these serials (at least the 1943 serials) is that you get a good idea of the anti-Japanese sentiments of the time. You'll hear terms like "japs" and "slants". You'll also hear mention of how "the government rounded up all the japs and put them in internment camps."