For upper class fashions of the late 1940s you can go no further than Andaz (1949) in which Nargis, Raj Kapoor, Dilip Kumar and Cuckoo play giddily modern Bright Young Things.

The centrepiece of the film is Nargis and the actress looks perfect in both Western and Indian clothes.  There are a number of 1940s influences from the sweetheart and keyhole necklines of the sari blouse (coordinated largely with synthetic saris, possibly nylons, lace edged materials and the like) to collared blouses to wide trousers to knitted jumpers and much much more.  The jewellery is minimal and Nargis as always wears her hair short. And don’t forget the cute dog. And two leading men:) Though Nargis is the lead, Cuckoo (who plays the bestie) has similar outfits.

Reviews of the film here, here and here including an entertaining take by a 15 year old.