I ordered the drivers side door latch from Chevy of the 40's before I read the above warning. It arrived a few day ago, so I decided to try it. It in fact did NOT work right. It would latch, but not unlatch.
My existing lock is so bad that I really didn't want to put it back on.
So I studied on the new lock for about an hour, got out my Dremel tool, made a few cuts, and gave the lock a few good whacks in just the right place with a ball peen hammer.
Blew it off and oiled it up. Now it seems to work fine.
I thought the quality of construction was not bad, but there were a few sharp edges that needed to be trimmed, a cutout that needed to be deepened, and the angle of the two sides of the lock body needed to be "adjusted" with the hammer so that they would fit the door right.
Think I'll look for a NOS one anyway.
Kurt