Thanks Rennis. If you were bound by an oath of secrecy regarding these matters, then you should have kept it under your hat in the first place. And I'm sure that you didn't intend for this to come across in any way as an insult to intelligence.
No worries. The information is "publicly available" in that the 1600's densho in question is available for viewing and can sometimes be copied for private reseach upon request at a museum in Japan. That being said we still like to be tight lipped to a certain degree (yeah it is "public", but it is still "our" info darn in) coupled with the fact that I don't entirely have a full grasp of the subject matter in the first place, hence my reluctance to get into it in more depth. No oath breakage, just avoiding sticking my foot in my mouth in the future
I just thought that the info was relevent in that it is one source of a Japanese art actually having more than one "universal" key.
BTW, the last reply's shortness was due to typing it while running out the door to work... Sorry if it came off sounding rude.
Random babbling mode off