Nice information! also very helpful. It seems these cables were added in 1964. maybe some did not have them? Found a bullitan about it and took a picture of them but still need the rear attach spot?
I think you are homing in! So there is a cable spring screw behind the horizontal section of the rear window that has room for a spring in front of it. I'll compare your pic to my top tomorrow. From what angle do you think view of 'BB' is from?
