Chris. With the NSS removed, did you take the multimeter (set at ohms) on the NSS itself? I would think if there is an internal break you could confirm that.
Lets break up what happens when you try to start it.
There's a wire from the NSS terminal on the relay to a good ground connection. Yes?
The click you hear. Is it the relay or down below (soleniod) in the starter?
Finally. When you start with a screwdriver. Which two terminals do you connect?
I think I know the answer but want to be sure