I understood Jack Theakston to say that Dr Jekyll would have been projected in 1.33, because that’s what theaters were doing at the time, whereas I understood Mr Harris to say that, if the sound was printed on film like with Mr Hyde, the aspect ratio had to be 1.19 to account for the sound...
There are plenty of contemporary references to this film, including in cartoons. I think the problem for the public consciousness were the precode aspects of it, and the decision by MGM to remake it and shelter the March version. I think this version is far superior