I don't know much about them except that the column shift is very rare. I think only fitted to 4-500 before they went back to floor shift. There was a story on one of the very early cj2a (I think it was the 12th one built) in JP a couple of months back might be on their website but I think they said only about 300 built in 1945.
But again I don't really know it's just what I remember from the story