Without paperwork or contemporary references (which are pretty slim), it's all speculation. There's no direct proof, but there is inferential evidence, i.e., the film itself in its released state. Clearly chunks of it have been split into two, rearranged, and scenes excluded entirely. That's not even arguable: the original script exists; photos of the scenes were shot at the time but excised (these were not posed publicity shots. Compare on-set photos to the studio shots in the "Memorabilia" thread.). and a carbon copy movie was made at the same time from the same script. It's not THAT hard to figure out what was changed-- or, for that matter, patch it up.

(Man. I don't remember anybody getting this upset at the re-edit someone did of MURDERS IN THE RUE MORGUE a couple years back. In fact, everybody said, "Oh! Now it makes sense!")