Give me a few more days and I can tell you with a bit more confidence.
As mentioned back in post #12, I went ahead and worked up a prototype for what I'm pretty sure this is. Those arrived today and are now verified and working great.
Then, as luck would have it, I stumbled across an original about 30 minutes later... I've mentioned before, I don't like working from best guesses or speculation, so that one should be arriving in a couple days and I can be 100% sure.
I got scalped, but sometimes we make sacrifices for science....
