Thanks!
The semi-short answer is that over the last few years ( V, X, Y, Z ) I’ve become aware that many of the resources once familiar to all in the 3D communities (because they were freely available to pretty much all) are getting harder and harder to find and import into today’s 3D programs (by which I mean Blender, 'cause that’s what I use, but still). For an on-topic example, in the 2010 article I linked to in the first post Rideout says “Obviously both of these models now exist in a trillion different forms and file formats.” – an exaggeration, of course, but ten years later I could not find one single free download of that elephant outside of Rideout’s patches.zip. Not one. Presumably Pixar still includes it as a test model in some of its products – I was unable to verify even that. (Granting that some of my failure to find it could be ID10T error – some, not all.) The loss would be staggering if it wasn’t so often snowed under variations of “Why are you bothering with that antique? If you want one so badly, why don’t you just model it yourself?”
You do? An Add-on Developer with over sixty solutions in Python Support fully supports my efforts. Well, this is an opportunity not to be missed! 
According to github an earlier(earliest?) version of add_mesh_teapot.py was added to Extra Objects in 2012. Like the current version, it appears to use two of the three Bezier data patches made by Newell and put up in 1991 by Juhana Kouhia in teaset.tar.Z – when I add the third patch, the teacup, it works. (Maybe it should be added to the official version – gotta look into that.)
I don’t hope to grasp more of how Rideout’s and D’Agostino’s code turn patch data into mesh, and I’m done beating my head against that particular wall. But I’d very much like a greater (read “any”) understanding of how python indexing works, especially as used in this add-on. Neither the Blender Python API docs nor the Python docs have been helpful (yet, I’m still working on it).
Although I’ve gotten what I wanted (re my solution-checked post above), I don’t know why my attempt to run all 2048 lines of Gumbo’s patch data through at once failed while doing it in eight 256 line batches succeeded. Looks to me like the way D’Agostino’s code put out the mesh in specified resolutions (res 5 may be more authentic, but I’ve found res 4 to be easier topology to work with) would be a good thing to have usable when (or if) somebody else wants to make mesh from old bicubic patch models in Blender.