Another theory
My 1950 with the mirror 5th hole was made in Oakland California
Here is a pic of another members 1950 oakland truck
...stovebolt pic... looks like he has the mirror 5th hole.
I’m not sure where Jockbolters truck was made, but his 50 has it.
Could it be that even in 1950 that California would require the mirror by law?
So the factory would thread the division bar for it.
I know it doesn’t much matter,
don’t want this thread to go the way of the proper 216 gray paint.
Any way the mirror is not adequate, it too small. That's why I use the larger clip mirror
