My dad hauled around a family of 4 in a standard cab. It also had a bench seat. He installed seat belts before they were standard equipment or even an option.
I’ll always remember riding in my uncle’s 1956 F100. It was pretty much a basic short bed F100.
It didn’t even have a headliner. Actual dimensions were probably similar to a Slate.
We loved it and thought it was the way all pickups should be.