i'm afraid that one good source of information i have, a photocopy of some jo textbooks i received from my teacher when i began training, is MIA. since i'm unable to confirm my suspicions, i'll put a few questions to the more knowledgeable folk here in the hope of provoking further discussion.
i don't remember what term was used, but i did read through the SMR headmasters' lineage chart in my above-mentioned source. each headmaster had a different family name, and recalling this i just reread the beginning of William Bodiford's excellent "Soke Thread" in the archives. it confirmed that the person who held the title of soke or iemoto was normally a direct descendant of the previous soke, and if no suitable male heir existed then a qualified member of the said tradition could be adopted by the family which controlled the it. since i don't see an obvious blood relationship between each headmaster in SMR and if my interpretation is correct, might we say that SMR jo has never had a soke as such but rather a hanke (to follow Mr. Montes' cue) or shihan? considering the current situation with TSKSR where soke and shihan are very separate roles, this may not be an altogether ridiculous suggestion.
as for the term hanke, i wonder if Mr. Hartman would hazard the same guess as i: han from shihan, ke from soke. if correct, this would make it sound awfully close to soke or iemoto. perhaps not surprisingly, there is no entry for hanke in the Kojien, so i don't have any way to offer immediate confirmation. looking forward to more comments and insights.
Jeff Hamacher
Those who speak do not know,
Those who know will not speak ...
So I guess that means I don't know a thing!