Chevrolet cars back in the '40's had a vertical push rod or button in the door that worked the lock. As I recall, it had a protection override in that you had to pull the door handle outside down to the "open" position to close and lock the door on the driver's side. While inside with the door shut, you could lock the door with the button then crawl out the right side passenger door. I think several states had laws about access to/from a parked vehicle on a roadway that required passengers to enter and exit on the passenger side.
The truck locks were as described, and it was fairly easy to lock the keys in the ignition with an inadvertent forward push on the door handle when getting out of the vehicle. Yeah, folks used to leave the keys in the ignition quite regularly, my grandpa always did. People in town knew that it was ok to move his car or truck if it happened to be in their way.
