I won...but not in the way I thought I would.
- I bought a set of spiral screw extractors from the Harbormaster
- Selected the one that would best fit the new plug, then ground the tip down to remove some of the sharp point to get to the starting diameter I wanted
- I tapped the extractor into the stripped drain plug head with a hammer (1/8" NPT, 3/16" allen) and I turned the extractor CCW with an adjustable wrench (all I had), all it did was turn inside the drain plug head, did not grip tight enough
- I ground down some more (grind more, effective diameter gets larger), tapped in, and it still turned, hole now larger
- Repeated the above grinding down the extractor tip/tapping into head of stuck plug a few more times, no success
- While lying there on the ground, it struck me that I better figure something out as this method was going to hog out the original hex head to the point where the top of the plug was gone. It also occurred to me to try tapping in a Torx 40 socket (T-30 did the trick on the other side, this one was larger now due to hogging it out with extractor). It worked!!!
So, I am grateful for having the wisdom to long ago buy a set of Torx sockets to work on my '79 CJ-5. ;-)