You're over doing the bleaching...they are starting to look 'minty white'
Most of these have 80 years of acid tanning, so I'm using the "remove color cast" command. You pick a spot that should be white. Sometimes I may be picking the wrong spot. Usually the borders should be white so that's a good start. But ultimately the goal is to show off the art for non-movie-poster-people. So I'm often cropping out some of the small text the bottom, whitening, saturating color slightly, "painting over" large sections, etc. The purists can download the originals from LOC.
Cleopatra (1934 US 1S Style B): Here's one that
EMP recently sold for $6,000+. Not a great poster design by itself but remember it was just one style:
Black Doll (1938/1940s-re-release US title LC):
Lemon Drop Kid, The (1934 US 1S): Obscure version of this movie, not a comedy contrary to the poster image:
Hell and High Water (1933 US 1S):
Bronze Venus, The (1943rr US 1S):