Sherlock Holmes - Dressed to Kill (1946) [colourised]

Three cheap musical boxes that were manufactured in Dartmoor Prison, and play slightly different versions of The Swagman are sold at an auction.
A criminal gang is plots to steal all three, and are willing to commit murder for it.
Sherlock Holmes must try to recover the boxes and crack the secret code contained within them.

This film is in the public domain.
Adapted from a story by Sir Arthur Conan Doyle.

Link to original movie:
https://publicdomainmovie.net/movie/dressed-to-kill-0