Door locks on my '62 C10

[jonzcustomshop]

the key lock only locks the button on the outside door handle.
to lock from the inside:
lift the handle up to the lock position with the door closed.
as a safety feature if you lock the inside handle, and then shut the door, it will unlock, that way yo can't lock yourself out.
you can lock your driver door while driving, but to lock it for security you would have to use the key lock on the button.