Need help finding a part



Its off a 68 A body steering column and I need to replace it.
I looked on rock auto and couldn't find it.

What is the piece called? And where can I purchase a replacement?
I bought a replacement turn signal switch but that's just the piece that attaches to the other part.
http://info.rockauto.com/getimage/g...geurl=http://info.rockauto.com/RB/5049305.jpg