The driver side outside door lock was not even a factory option on a Dodge truck until around 52. The handles with the locks that are available for the 39-47 and the early 50s only lock the handle movement and use a square shaft. Those are very similar to the lockable Ford door handles for the 28-30 Ford model As, but with a different screw plate to hold them to the doors. The Ford pair are cheap, the Dodge handles with keys are 4x the money. For the record, the Ford one turn the handle 90 degrees, they worked but looked really bad.

The Dodge driver door can be locked and unlocked with the inside handle. The available door handles with the keys only lock the handle itself. If the door is locked with the inside handle, the handle with the key will not unlock the door. You either have to figure out a way to disable the inside door lock, or get into the habit of just locking and unlocking the handle.

The next option is to put an electric key fob locks on the doors, not sure you could do that with the OEM latches.

The headlights are easy compared to he door locks.