That French Frankenstein was in Robert Florey's collection. I met with his widow, and she explained that he wanted one poster each from all his movies, and he had a U.S. poster on ALL except Frankenstein, because Laemmle had cheated him terribly, promising him to let him direct him he gave Laemmle the script, but once he did, Laemmle took him off of it, and to add insult to injury did not credit him for his script!
But he somehow DID get credit on the French poster, which was why Florey had it in his collection! Interestingly, he was a major collector of other types of items, like swords, but the only posters he had were the one each from his movies.