1: Could George Banks have afforded his lifestyle on his salary? I don’t know what kind of money junior executives at a London bank made in 1910, but surely it couldn’t have been enough to afford a parkside mansion in the city AND pay three servants, could it? Today such a home in London would fetch, what, ten million pounds?
2: The jacket that Bert wore on the country outing sequence- was that just some fanciful outfit that was added because Disney wanted color, or would fashion styles of The Day have called for such an outfit when going to the country?
That sort of house (and servants) was typical of the middle class of those days. Housing was cheaper and servants cheaper still. Admittedly, it may be a bit idealized, but it wasn’t out of the question.
Just a little. I would peg Mary Poppins as Edwardian. The giant hats (think Julie Andrews in the animated sequence), the parasols, the stand-up collars.
Even though the illustrations are in black and white, you can get a pretty good idea of the jaunty striped coats worn on boating outings in Three Men in a Boat (To Say Nothing of the Dog). If you click to chapter 6, there is a picture of a man trying to climb up out of a hedge maze.
There are also photographs (also b&w) of the author and his friends in their sporty jackets.
This kind of country outing clothing would have seemed familiar, although possibly slightly old-fashioned, to the Banks of 1910. I’m trying to remember if anything in the Mary Poppins books fixes a date for those.
Edward VII died in 1910. Given Mrs. Banks’s involvement with the Suffragettes, I actually thought the movie might be set a bit later, perhaps just before World War I: Suffragette - Wikipedia
You have to pay attention to the songs. In Mr. Banks’ first song he sings:
“King Edward’s on the throne
It’s the Age of Men
I’m the Lord of my Castle
The Sovereign
The Liege
I treat my subjects – servants, children, wife – with respect Noblesse Oblige”