Andy, you may be able to buy matching door locks and keys from www.vintagepowerwagons.com or at least you could a few years back. The vintage Power Wagons used the 39-47 cab, but the more modern key & locks were an upgrade they offered, at least for a while.
Outside driver door locks were not even available on trucks until the 52 (or 53) model year and were an option for several years after that.

I bought and installed a remote power door lock kit on my 49. Haven't used it a lot yet, but that will change this coming summer.