er... I know we're talking about ADs here, but my 46 has a lock in the door on the passenger's side, and a lock in the handle on the driver's side.
AFAIK, it is original.
I know that they moved the lock from the handle to the door on the passenger's side in 42. Did they put a lock on the handle on the driver's side prior to the 47 AD run?
If it was an option, I think I have an explanation. It was originally owned by a railroad, and there were a few other bells and whistles on it that have broken (or are missing).