Welcome! This is a .38/200 British Service revolver from 1941 (I think - someone here will have a more exact ship date). A very similar gun except for the finish was named the Victory Model, so many collectors call this a pre-Victory model. These went to England and other Commonwealth countries, so yours might have went to Canada and stayed there. Hope this is helpful.

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Alan
SWCA LM 2023, SWHF 220