Well, vacation was nice, thanks. Arizona is much more diverse, with respect to landscape, than I thought. On top of that, it's been above freezing (way above freezing on some days) since I returned an a lot of that snow is melting nicely. Perhaps Punxsutawney Phil is right after all.
So, after formulating different scenarios, in my head, in an attempt to find a rack mounting solution, I gave up and decided to just use a backpack. This isn't my favorite solution because the backpack will prevent my motorcycle jackets from properly venting air (to keep me cool) and my backpack isn't waterproof (should I be caught in the rain). Recently, I went "shopping" on that big, on-line auction site and discovered this (at right). That's a (dingy, used) rear fender off of an '89 NX 125. The more I research, the more I discover; it seems that '89 (and '90?) models came with a rear rack from the factory. Those little black dots (as indicated by the yellow arrows) are actually grommets where the rear rack would attach from underneath. Just to the left of those attachment points (on each side of the fender), you can also see where the turn signals attach. I already know that the factory rack used the seat bolts as a forward attachment point. Since the frame ends right where the turn signals attach (and the sub-frame that continues aft [toward the right, in the image] is too light/weak to support a load) I have to think there was some type of (inverted) "U" shaped bracket, under the fender, that tied the frame ends together from side-to-side. That would help distribute the load, to the frame, and can't be too hard to fabricate. I'm also in contact with my engineer brother-in-law (who also rides) to see if my mounting idea will pass the "stress" test.