Got the job done. The noise was the right-side hub bearing assy, after all. Replaced it after work on Friday, along with lots of PB Blaster, new hub bolts and a new 35mm hub nut, and torqued everything to spec. Job went well, after my learning curve on the left-side hub. Saturday I went back to the left side, replaced the three hub bolts, and retorqued everything to spec, as long as I had the new bolts and still had the tools from Autozone.
All told, I'm not sorry to have replaced the left side. If I had guessed right the first time (right side), I think I still would have thought I ought to do the left side also, for completeness. Sure can't kick after 188,000 miles.
Got the hub assemblies for $90 each from MI Bearings, right here in Traverse City. Their web site makes a point of saying their stuff is made in USA. Brand was "Wheel Bearings, Inc.", made in Gaylord, 60 miles from here. They look good; hope they wear well.
Thanks for the tips. They helped.