The two series of exterior door handles on GM trucks between the years 1934-46 are certainly different yet they share a few similar features of interest.
One characteristic which seems strange today is that the handles lock the right doors only, not on the left. This occurs on GM trucks from the early 1920's to about 1959. At this time, we have no reason for this feature. Maybe it kept the driver from standing too near traffic as he locked the door!
The 1934-38 handles are the same. The left has no cylinder key but the right handles are the locking style. Yes, the right and left handle will interchange but this is not the way it was done by GM. Switching handles would prevent the right door from being locked. There is no inside lock on the right!
With the introduction of the new body style in 1939, the handle design also changed, however the locking and non-locking handles remained in the same position. The big change started in 1942.
GM decided that rough roads plus freezing in the North caused too much lock breakage. The die cast lock parts inside the handle were too easy to break. During that year, the lock was moved down into the door skin. Both right and left handles became the same non locking design. The following photos show this big change in door locking on Chevrolet and GMC trucks.
Door Handle Trivia
The locking key cylinder used between the years 1934 to 1941 is the same despite visual changes in the handle body. Of course, if the truck is right hand drive, all is reversed!
1934-1938 Right Door Locking Handle
1939-1941 Right Door Locking Handle
1939-1946 Left and 1942-1946 Right Non-Locking Door Handle
1942-1946 Right Door Handle (lock in door skin)