Regarding the burn marks, those were added to the prints and not the original negatives. They were there for use by cinemas that used older projection systems that used two seperate projectors instead of the single large platters in order to accomodate multi-reel films. The first burn mark would indicate that the reel is about to end and the second mark would tell the projectionist to start the other projector and switch off the one that was running. All of the film prints that were sent to theaters at the time would have them but if the transfers were off of the negatives and not a film print, the burn marks wouldn't be there.