Well.... I did it.
And I couldn't have done it without all you great folks on this forum.
Let me share a few photos and a bit of backstory. This is going to be a long one, so grab your favorite beverage, and sit back.
The connectors arrived Monday, and I knew that with my work schedule, today would be the first opportunity. Early this morning, I dismantled the back end of the bike, to get access to the PCBs for the rear turn signals. I had my wiring diagram handy, and the service manual. Took me a bit of wrangling to get the covers off, so I went and bought a flexible screwdriver. Made it a piece of cake.
Let me tell you, it was hell the ruggedest mile to get those plugs into those sockets. I ended up taking a Dremel tool and carving out the end of a bamboo chopstick to make a holder for the plug so that I could maneuver it into the socket. I also found that there was a very tiny rib along one side, (less than a millimeter or so) preventing the plug from seating properly, so I took an X-acto knife and shaved the rib off. Fit the plug into my homemade installation tool, and it slid right in. Seated perfectly.
I reasoned that since the pumpkin-stalk turn signals already had connectors (of the bullet variety) into the wiring harness, that I could re-use them in this application. So, I removed the stalk turn signals, and clipped off the wiring leaving about 4" of wire and the connector. It was at this point that I decided that I didn't need to leave the covers of the PCBs off any more, so I drilled a 1/10" hole in each one, and threaded the wires from the plugs through them, and reinstalled the covers. I put a bit of silicone over the holes, to prevent water ingress.
It was a simple matter of then determining exactly what the polarity was, and so I took a break, and came in to research it. I found a neat little device on Instructables that enables people to light up for test purposes, 12V LED lights. Made from a power supply from a printer, no less. A couple of alligator clips soldered on, and I was in business.
It so happened (I put it down to blind luck) that the way the plugs fit into the sockets, the red wire was the hot one, and the black wire was the neutral, so all I had to do was attach the correct colored wires with the bullet connectors to the ends of the leads. I think I did a pretty good job, even though I'm by no means an expert at soldering. For the record, I watched a dozen YouTube videos, and practiced on several different wire connections for about an hour before I felt comfortable doing it to the bike.
I kept using my little testing device to check connections at every step of the way, to make sure the LEDs would light, before I'd go to the next step. I used heat-shrink tubing and a heat gun to cover up all the soldered connections, both for added strength and for moisture protection. Can't be too careful when one really doesn't know what one is doing.
It wasn't long before I had connected up everything there was to connect, and reattach the bullet connectors of my leads into the wiring harness. I reconnected the battery, and turned the key, and it actually worked! Un-freaking-believable! And I did it! (with this forum's help and advice!)
Here's an image of the lights lit up.
I wanted to upload a short (11 second) video of the lights working, but I couldn't get it to upload.
Anyway, I wanted to thank everyone for all their advice, assistance, and for the generous and freely given expertise and knowledge.
Thank you all!
Now, on to the front signals... I am still waiting on the housings to be shipped in from Japan... I think they're using an old rowboat to send them...