Mmmmmm, let's see. During WW2 they were shooting 16mm color, black and white, 35mm color, black and white, 35mm 3 strip technicolor. Some of the footage was grainy and shaky. Some was scratched. Some of the combat cameras had very poor quality lenses with no coatings that gave the film an overall softness with glowing highlights. Some footage was shot at 16 fps, some at 24. Many of the cameras used in combat had spring motors. Much of the footage from the front had dirty gates, There was a lot of damaged film. There's a lot of film that has been damaged by time and poor storage. The point of this ramble is that I'm not sure what you want.
A frame grab of the look you're trying to emulate would be helpful.
There are plug-ins that simulate film damage, worn gates, grain, and other problems. The Color correction tools in AE give you control over black levels and color. You'll want to separate fields to remove the interlacing. If you want to convert to 24P you'll need to look for some tutorials on how to do that with AE's native tools or purchase something like Magic Bullet. I don't think I've answered your question, but maybe I've given you some ideas.
Try this and tweak to your heart's content:
Rick has a point, though: There's no single specific instant 1940's look. It all comes down to what film stock was used and some of it is amazingly clean and pristine...