Tom R,
Interesting. I guess my question would be the same as your question...what is the third terminal for. With a meter, you could map the terminals which might give you a clue as to the intent of the switch.
I have heard the famous story about farmers being able to turn the key on, remove it, and have the ability to jump in and start the rig sans key!
This doesn't make too much sense to me, plus it seems like the coil/points would be short lived.
My guess is that "off/unlocked" is the equivalent to today's ACC position.
Stuart
