Thnaks for the encouragement, guys! The wife is already resigned to her fate. ;)
Well , things are progressing nicely! I've gotten in touch with the blog writer, he's apparently a housebuilder/carpenter in Iwakuni, where the mine is. He seems really friendly...perhaps a guide? :D He uses a full range of local stones for his planes and such, apparently, from rough to fine. There is even an aoto mine around here, he says!
Also, from that same blog, I have met a total honing-geek. He has his own blog all about honing kamisori, knives, axes, anything with an edge. I am taking notes...but according to him, the Iwakuni hones might be a little soft and rough for kamisori; they are finishers, though, above 10K. Just not in that special Japanese natural range of 30K or so. However, softer stones might be fine for razors, as you use less pressure than kamisori, right?
This is one HECK of an awesome rabbit hole! And I shall keep on down.