Swim suits now no more a strange thing. Nutan wore a swim suit in the movie Delhi Ka Thug in 70s.
Even vaijayantimala wore it in sangam in 1970s but to hear someone wearing it in 1946 is unimaginable.
Sangam was released in 1964. Dilli Ka Thug was released in 1958. By the time Vyjayantimala wore a swim suit, people and spectators were much used to Swim suits and Bikinis. Because Nutan wore a swim suit already as early as 1958
The emergence of swim suit in 1946 did not make the people rise their eyebrows because the swim suit was born in Western countries which is a much free and permissive society.
A swim suit in 1946 was as common as wearing a Suit.
You yourself wrote Delhi ka thug in 1970s. But still I have seen people raising their eyebrows when they see actresses in swim suits in films I can't imagine their reaction if they would see someone wearing it in actual.