The film's loosely based on the life of Madeleine Smith, whose story was told more fully in David Lean's film Madeleine (1950).
The film is one of many which the original copyright holder failed to renew the film's copyright, which resulted in it falling into public domain.
The headpiece Hedy wears the first time she walks in the office is a 'snood'. It was very stylish in the mid- 40's.
Ms Lamarr was a woman truly ahead of her time. She was very inventive, and wished to be taken more for her intelligence than her looks. It was due to Ms Lamarr's creativity as the inventor of the technology which underlies almost all modern digital communication which she wanted to be remembered for (she was sadly, noted for this belatedly - after her passing).