Thanks Marty and myhondas,
So here's an update from my end. First, my cousin said she doesn't speak enough Japanese to help me out, so that's out the window. Second, I found that Yamyia sales a Japanese version of the parts list. It probably spells it all out nice and clearly in that particular version. I'm considering buying it.
Myhondas, you're right. There are definitely extra sockets in that picture, but I think there may be two harnesses in the photo (maybe a speedo & tach?) with the 8th socket hidden by a shadow or something. Also, since I last posted, I visited a friend in Atlanta that restores and customizes 750's. While I was there, he said, "Here I have something for you" and pulls an indicator light off a shelf. It has the red housing, the screw on plug, bulb, and wiring. It's a completely self contained unit. I couldn't believe it. I don't know if it works. the plastic is cracked and the one of the male plugs is missing, but it's a start.