Resurrection of the old Reverse Light Thread

So, I am resurrecting a 2018 threat on the reverse/back-up lights.
Barracuda Reverse Lights

On my new-to-me '67 Notchback the reverse lights are not working.
I am diassembling them, and only finding one wire coming from the trunkleading to the lights.
The lights themselves have a several wire pigtail, at least one of which has an extra female connector.

**Problem is that I cannot detect any power in the wire coming from the trunk when the car is placed in reverse.
And now the tail lights are staying on. (So, I'll disconnect the neg battery cable for the time being)
:(

**At this point, I am thinking that the pigtail of wires is a multifunction connection that is designed to be used across the years, including when the reverse lights are part if the tail light assembly.
**Anyone with any knowledge on this???

And, to boot, the tail lightsockets are rusted solid.
When I do figure it out, I'll probably replace them with and LED socket and bulb.
Bezels and lenses are fine.