I saw "M" in 1952. The theater in LA was picketed because Joseph Losey was Blacklisted by the McCarthy Committee, and the film wasn't shown again after that week. I don't think it's been shown since then, and it's probably difficult finding a copy. I hadn't seen the original, but I was very impressed by this film, especially David Wayne. The attitude of the mob, especially the women, was expected. But I was surprised by the speech of the "defense attorney". Even today, people would be vexed by his sympathy toward this mentally disturbed criminal. When the original "M' was shown, the Nazis were coming to power, but Lang was able to escape to the USA. Joseph Losey, however, wasn't able to escape the Blacklist. Was this version of "M" meant to foreshadow the "new order" of McCarthyism?
