I was just thinking about my old 53 and remember this incident. My mother was sitting in the passenger seat and I made a left turn kind of quick. The passenger door flung open and I almost lost my mother. It was a 4 door. A friend of mine (now a SK) had a similar experience in a 2 door. the door flung open, his friend grabbed the seat, and the seat bolt pulled thru the rusty floor. He grabbed the top of the door frame and was OK.
After this incident, I bought a new latch and fitted it properly but never had confidence in it. It was a terrible design. On an old 1950 in the wreck pile I found a new improved latch that I installed and never had any more problems with mom falling out. I can't remember this latch but it was similar to to the 1956 design and wrapped around the sprocket somehow.
I also slowed down going thru corners.
After this incident, I bought a new latch and fitted it properly but never had confidence in it. It was a terrible design. On an old 1950 in the wreck pile I found a new improved latch that I installed and never had any more problems with mom falling out. I can't remember this latch but it was similar to to the 1956 design and wrapped around the sprocket somehow.
I also slowed down going thru corners.