It seems to look similar to the 1957 version, the thinner column post should have like a finger tube with a hole, there is a spring and two little caps that go into the tube. there is a rubber insulator that goes on the top of the end of the shift arm, that assemble gets wiggled into the finger hole. I'll about taking pics of mine. It was what a wedge in fit when I replaced the rubber on mine. I want to say it's all held with the spring pressure.
See pic