I’m back. I took a picture of my rear latch last night. The lock is held in with a spring clip just like the front doors. The spring clip can get pushed too far into the opening. You may need to use needle nose plyers or a pick to get at it.
I took the mechanism out to have a closer look today, which brought a new dilemma to mind. The lock is attached by a clip inside the door.
This makes me thing the shaft is missing, or was not engaged in the latch mechanism. The shaft on the front door locks (’47-’51) have a paddle end and engage with a bowtie hole. The shaft on the barn door does not, it is the square profile with one corner flattened. It engages with a small hole in the latch mechanism.
I don’t know how you could remove the mechanism before the lock.
In my picture you may be able to see a small hole and indent on the door interior where the lock shaft lines up. Presumably where a locksmith punched out the lock. I could not have lined up my lock shaft without that hole, it was difficult as the lock shaft droops during installation.
The ’47-’51 barn door latch mechanism is similar to the front right door of ’34-’46 Chevys so a spring from that era will work. Here is a link to that anti-sag spring:
https://oldchevytrucks.com/dp146r.htmlMy barn door handle never sagged. I cleaned it up and then it sagged. I replaced the spring and it sagged less. I think it needs to be gummed up a little to get the sag out.
