Re: "Hidden in Plain Sight" - Shinkage ryu menkyo
So it was, in fact, a Yagyu Shinkage Ryu document and not something that Takeda had a scribe write up special for Ueshiba that he just called a "Shinkage" menkyo.
It was furthermore a document related only to the Edo branch of YSR. Therefore we might as well take Kosaburo out of the picture here, because he was an Owari man and the scroll in question was meaningless in his tradition (as far as I understand it the two branches had been fairly separate and distinct for over 200 years at this point).
How illiterate was Takeda? I've read in HIPS and in other places that Takeda spent a lof ot time wandering around crashing dojo. What was it like to manuver that particular landscape and not be able to read? Did he have the occasion to lay eyes on a lot of different documents from the various ryu he encountered in his life? He must have developed a knack for eyeing a scroll and coming to some conclusion as to what its signficance was, even if he couldn't appreciate all the characters.
What if Takeda had no idea what the document was in the first place? Maybe he misunderstood what it was? Maybe he didn't care what it was, he just thought it was a nice scroll, written on nice paper with good clean brush-strokes?
I take it there weren't a lot of students around who would have been comfortable saying, "Ah, Sensei! Chotto..." when the old man was wrong about something?