And the part number matches the part I was referencing.

1 hour ago, SteveJ said:

And the part number matches the part I was referencing.

So... we're thinking inhibitor switch and relay for the second set of points?

Here's a diagram from the 72 Emissions chapter. It shows a wire going directly to the distributor from the relay.    The ammeter they show is a separate one, for diagnostics, not the one in the car.

So, you could trace the wire back, or compare colors, or disconnect and test continuity.  Or a combination of those.  Or you could do a variation of the test as shown in the chapter, and see if the relay has an effect.

Not the relay for the second set of points. That is near the front of the car. It's the relay for the inhibitor switch. The green wires go to the seat belt buzzer. One black/yellow wire is from the inhibitor switch. The other two black/yellow wires complete the circuit to power the starter solenoid. 

When the automatic transmission is in Park or Neutral, the contacts should be closed on the inhibitor switch. When the key is in ON or START, this energizes the relay called K-18. The contacts close on the starter solenoid circuit so that the car will start in the ON position.

I'm the guy with the question on this item. Thanks jfa and all who brought clarity to my inquiry! Unless this is one of those components that has extraordinary durability, I'm sure I'll have more questions later if I can find a replacement. By the way, it's a one owner car mine since new (72669). I put it in storage in 1983 and began a preservation project about 12 months ago.