If you look at the top of the column by the steering wheel, you will see where the diameter is smaller and a small hole has been punched in the tube. The upper bearing/bushing sets on the tang of metal from the small hole, and the small diameter is where the bushing is pressed into. The original bushings (no bearings) is made of a wood type material with some sort of leather like stuff on the inside where the center shaft rides. On top of the bushing is a brass ring with a few ears pressed into the bushing to hold it in place. One of the ears has the horn wire soldered to it and the wire runs down through a hole in the bushing. Its all insulated from any metal. The wire runs the length of the column and exits just above the steering gear on the frame side. http://chevy.oldcarmanualproject.com/1929_54chevyparts/06/395.HTM

Joe