May I ask where you got the Takaoka quote from? I'd love to hear what can you share about Takaoka and O-sensei especially where ken is concerned.
(BTW, I don't know if Ernesto told you but, we were both in the Netherlands at the same time this summer. Ernesto and I were talking about you and we all could have been talking together! Maybe next summer we can arrange in advance to hook up.)
Have a look at this website: http://sighar.net/aiki/syumi04.html
Since I have retired, my summer vacations are longer and the dates of my coming to the Netherlands more flexible. However, since I am looking after two groups, as well as my own dojo in Hiroshima, coordinating dates might be a problem, but a surmountable problem.