Early S-W tach wiring help request

Getting ready to install this old 60's Greenline tach in my dash and realized I don't have a wiring diagram for it. It was their first transistorized tach that didn't require a sender and has only two wiring attach posts, neither of which is stamped or identified on the case. I'm guessing one is to the coil and the other is ground but which one?
Anybody out there got an old S-W wiring diagram for the "960 Series" one piece tach shown below?

 

I'll bump this back to the top. I've got a similar SW, and I'm wondering how to wire it too.

 

Bump,,,also does this one need a Tach Filter? I cooked a few 'til I used them. I have a different SW now and will use a mid 80's Monte Carlo tach filter(off ebay). It knocks the sharp spikes off the firing signal which damages most tachs.

 

I googled stewart warner 762 tach and my information. Cal

 

i think your right,+ side coil,ground