It sounds like some of the surprising door openings may have been caused by:
1. A loose latch/catch?
2. Grabbing/pushing the door handle at the wrong time and inadvertently opening the door?
Having the optional/accessory arm rests might help in some situations. You would grab the arm rest, not the door handle?
Also, during the 1948 model year, the action of the inside door handle was reversed, supposedly making it more easy to operate. From 48 onwards, the door handle was pulled to open. Was this change made for safety purposes (or, did it result in surprise opening of the door when the handle was/is grabbed when going around a corner or when coming to a stop)?
