The Three Cases of Murder release is 1.33 - 1 . The DVD case states 1955 but the the release date on the movie´s credits is 1953 .It looks like the print source is from the US,because after the title card "London Films",there is a second title card "Janus Film".When one considers the low budget of the movie,and that Cinemascope was virtually brand new in 53 and VistaVision came along 54-55,it seems unlikely that it was made in any kind of wide screen.
As I say the quality is good and the ratio looks correct. There is no evidence of stretching or other problems - it looks natural. There is so little technical information available.Return to Glennascaul is also 1.33.-1 and a good print. As we are on the subject of aspect ratios - do you know which ratio is presented on the French issue of Chimes at Midnight ?
I live most of the time in Germany and I am sure that I once saw (in the mid 70´s) a German dubbed "Chimes" but in Letterbox format. Or am I dreaming?