I love these covers by Alex Schomburg, especially the science fiction one, where the woman has a 1940s hairdo. There's a collection of his illustrations, called The Thrilling Comic Book Cover Art of Alex Schomburg, published by Vanguard.
This is a page from the detective story. For the moment I have a lot of these, where the characters are more or less drawn but the background is still missing. This is usually how I work: the characters first, and then I'll go outside and find a street or whatever is needed and draw that in with pencil and then go back home and ink it. For you aspiring cartoonists out there, this is not a method that is recommended! Rather draw the setting first and then place the characters into that, okay?