You did notice that Reverend's from the UK right? So he might be going on more than a sitcom ( mentioned in jest) and know more than someone from Columbus, Ohio.Clearly, you have no idea what you're talking about mate.
I know this may be difficult for a non-Brit to grasp, but Michael Caine is working class. The bank balance, the fame, even the knighthood, none of it can change that. It's not about where you are, it's about where you're from. It's not about how much money you have, it's about how much money your ancestors had. It's heritage and it's cultural. You can up or downgrade you standing in society, but it doesn't change your class.
In Britain in the 1940's, '50's and even into the 60's, your accent said everything about you. It said where you're from, what your background is and whether you were born into poverty, comfortably well off or with a silver spoon in every available orifice.
An accent can be a badge of pride or a mark of shame depending on which circles one aspired to. People would (and still do in some cases) try to suppress their accent if they don't want to let on they're from poverty. All those snooty English butlers you see in movie and TV? Most of them are put on. For the knobs, it's not the done thing to have a servant with a common accent in front of guests. Remember how Parker in Thunderbirds would have the snooty accent when addressing Lady Penelope, but would slip into cockney the second he spoke to one of his old mates? True to life, believe it or not.
To give you an idea on the level of stigma that could be attached to it; Until the late 60's/early 70's you'd almost never expect to hear a regional accent on TV or radio outside of a broad caricature.
As for her Rank: that's something she would have earned through her education and proven aptitude. The most educated woman in those days (and mostly these days too if I'm honest) are middle class woman. Working class women generally had to work young and couldn't afford to go to school and the upper class for the most part didn't bother because they didn't have to.
For further reading on the British class system, I refer you to The Two Ronnies.
Whatever background they decide to make up for Peggy after the fact, Hayley Atwell is quite clearly playing her as a very middle class, grammar school girl.
And yes, Jarvis is almost certainly middle class too.
Yeah like a sitcom is a great place to understand anything the country it's filmed in. Peggy to me is too polished to be a middle class girl, if anything she's the black sheep of a high class familty. But I'm willing to wait and see what they come up with fr her.
Yeah let's keep this about Peggy Carter though.