I changed over my '56 (push button type) so I'd have outside locks on the driver's side as well as the trucks didn't come with driver's side locks. But both doors had inside locks (flip the handle). By changing both locks at the same time, I got them keyed alike.
However, what I DID sacrifice was the ability to lock the doors from the inside and use a key to unlock them from the outside. The inside lock mechanism operates differently from the outside lock.
