With a Swede, a Frenchman and an American in the main roles. But it does have the atmosphere.
I was going to recommend Dead of Night, but someone beat me to it, so I’m going to recommend The 39 Steps. Shows a bunch of different classes and surroundings, from a modern flat to a Scottish croft to a manor house, music halls, pub/inn, and of course Scotland Yard. Good suspense, typical early Hitchcock.
Roddy
Much of Random Harvest, especially the first part, with amnesiac Ronald Colman wandering around in the fog as he tries to figure out 1.) where he’s going and 2.) how not to be returned to the asylum. Ronald turns out to be pretty rich and quite a few scenes are set at his family’s manor house, with lots of chafing dishes.
If you want to go back to 1932, there’s The Old Dark House, a creaky old horror/comedy/thriller, with Boris Karloff, Charles Laughton, and a stunning young Gloria Stuart (need I say the old lady in Titanic?). There most certainly is plenty of ‘atmosphere’, fog, servants, dressing for dinner. The Rocky Horror Picture Show seems to be based on this oldie.
Waterloo Bridge with Vivien Leigh? Not all of it, but there’s some of what you are looking for in this wonderful movie.
Went the Day Well? is a great picture of the English countryside during WWII. An even better one would be A Canterbury Tale made by the previously mentioned Powell/Pressburger.
These are great ideas! Can’t wait for that first rainy day when I can light the fireplace!
A Canterbury Tale is a lovely, quirky film.
Neither is Laura, which the OP also mentioned. But fair play to point it out.
Of course, The Ghost and Mrs Muir has to be on your list. sigh Captain Gregg…
Portrait of Jennie is set in America, but an atmospheric movie.
StG
Or, you could try to find the original version, made in England in 1940, starring Diana Wynyard and Anton Walbrook.
I actually cannot stand that movie, as the studio forced Hitchcock to tack on a ludicrous happy ending. In the original book the bride *knew *her husband was a serial killer, and her decision was whether or not to just let him kill her.
Not a fan of Suspicion either – haven’t seen all of Hitch’s films, but all that are available to me since a kid.
Here’s an excellent one – one of the best film noir-style movies, and one of the best, period. Powell and Pressburger, The Small Back Room. Eminently English (spits on floor, being half-Irish), best movie short of Rio Bravo about drinking, and a damned good war-time movie as well. Gorgeous photography.
No, I’ve never seen any film of one of Christie’s novels that meets the criteria.
Oh, thank, I love Gaslight, except that I hate everyone of the characters and actors. I would love to see a version I can enjoy.
I intend to reference this thread often over the next few months. I love curling up with a black and white with dialogue.
Those were both produced at the old Ealing Studios. A look through their archives will come up with a lot of titles that would suit the OP.
Thanks, I didn’t realize. I’ve seen quite a few of the movies listed in that link and I like most of them quite a lot. The OP couldn’t do much better than these for genteel British comedy.
I actually hated the original. Thought the acting was blah and overall it was just a lackluster film. But if you didn’t like the acting in the remake (personally I thought Ingrid Bergman was achingly vulnerable and highly watchable as always, I loved Boyer while despising his character, and Joseph Cotten is as yummy as in almost everything I’ve seen him in), we probably have differing preferences so you might like it. 
Oooh, I came in to suggest this. I saw a restoration in the theater a few weeks ago. It was fantastic to see on the big screen. Besides the look of it (the OP will swoon) it’s a fascinating story too, about how a small village takes on occupying Nazis.
Parts of Charlie Chaplin’s excellent black comedy Monsieur Verdoux are set in the English countryside. No “Little Tramp” here, he’s a serial killer!
Filmed 15 years after the given time frame, but Village of the Damned has pretty much what you’re looking for.
I know this is an old thread, but I’m so glad I found it! I’ve been on a 40s movies kick lately, and especially love the English, atmospheric ones. I’ve seen a few mentioned here, but I’m excited to watch a lot of the other ones too! 
Welcome aboard! Come back and tell us how you liked them.
Glad you started this thread, TLou Some great ones have been suggested and I look forward to seeing those I hadn’t heard of before. May I add Brighton Rock. They did a remake a few years ago that was ok but the original has wayyyyy more of the atmosphere I think you’re looking for.
Thanks ThelmaLou! I’ve seen Rebecca, Laura, The Old Dark House, The Innocents, and I think a couple others mentioned here. Right now I’m watching Portrait of Jennie on YouTube. Another good one that I don’t think is mentioned here is The Spiral Staircase (the original version from 1945). It’s an American movie though. And another one I recently watched was called "Ladies in Retirement ". It’s a very strange one but I loved it. And very atmospheric. If you haven’t seen or heard of it, here’s what IMDb says about it-
“Based on the play by Reginald Denham and Edward Percy, this drama focuses on Ellen Creed (Ida Lupino), a housekeeper who looks after Leonora Fiske, a retired actress living in the English countryside. When Ellen’s eccentric sisters (Edith Barrett, Elsa Lanchester) visit their sibling at Leonora’s home, tensions soon lead to murder. Though the death is carefully covered up, will the murderess get away with her crime, or will she be brought to justice?”
Oh another pretty good one I recently watched is called A Place Of One’s Own (forgive me if it’s already mentioned here). Another British ghost story, from 1945.
The next one I want to see is The Uninvited. It sounds like a good one.