These photos are demonstration only.
When I took the NCP apart, the wires were lying in the channels so:
You can see the puncture marks from the NPC connectors. The aftermarket power cord (APC) did not have piercing connectors. Instead the wires were soldered to the connectors. When the cord was placed in the channels and the top of the NPC was screwed back on, the pressure pierced the cord, making the connection. Elegant.
Note that there is a break in the top cord, skipping #2 entirely.
I erroneously thought that the wire in the middle should cross over. It rather looked like that was how the APC cord was wired. I spent two hours yesterday trying to re-solder theses connections using 18 SPT1 wire. I did it, but I did it wrong and ended up no closer to the solution. I also learned that I do not want to try to solder wire to copper connectors, ever again. TYVM. (Now that I examine this photo of the APC, I see that it appears as if there is a wire wrapped around the top cord at the left end, essentially connecting those two wires to each other and the terminal connection.)
See how the top cord, coming from the right, connects to 2 and 3, then has a break before it connects to 1? The bottom cord connects to all three all the way through.
Thanks to the folks at the Necchi Yahoo group for the photos of the correct wiring. If I understood current, connections and wiring I probably would have figured it out just by looking. Or, if I had remembered how I wired the power cord and foot controller on the FW, I might have figured it out. But I didn't .
Better yet, if I had just called my dear friend, Andrea, she would have set me straight right away over the phone. But I didn't think of any of those things.