Doug,
To answer your question "How did GM wire the switch", to the best of my knowledge this SWITCH was used from 1936 - 1955.
If you want to use the screw in type, buy a new one(less than $10). You will be better off with new anyway.
Harold
http://www.jegs.com/i/JEGS-Performance-Products/555/63070/10002/-1

Check your local parts store, they probably have one in stock.

Last edited by Harold46; 05/03/2017 9:46 PM.

Harold
Is a restoration ever finished?