Time for some contributions on my part: Watched "Niagara" the other day. Thematic connection is the mistaken-identity plot and a blond vs. brunette theme. Latter stroke me as quite substantial - spoilers: First we see a blond girl (Marilyn Monroe) sleeping in her bed inside a cabin. Later that cabin is occupied by another couple. The villain, while in search for the blonde, now finds the dark-haired one in the bed (it's the bed on the far side though).
You can check out the scene here (starting from 8:00). Watch for the similar camera work when that guy enters the bedroom versus Rita and Betty finding the corpse.
Well, that's it. The movie itself was nothing special or worth a note in DL's book if you ask me. But I had the same feeling about "Mon Oncle", so what do I know?
guy coming into a room thinking his pretty wife is there only to find another pretty woman curled up sleeping on a bed facing away from him involving a room switch-a-roo. That's somewhat similiar to The Cowboy finding the pretty girl curled on the bed in MD. The difference being that in Niagara she doesn't die or wake out of a dream. Another nice connection is Monroe's character faints and she can't share the truth of what she sees/knows. Sort of an imposed silencio with Del Rio hitting the deck.
Certainly Niagara's noir elements are going to have a loose vibe with any noir elements including those within MD. Regardless it was an interesting film to see and I was totally into the brunette.