Re: "Hidden in Plain Sight" - Shinkage ryu menkyo
Josh - Fantastic information. If enough copies of the book sell to ever warrant a reprint, I will correct the information in the new edition.
Barring further info, I would still stand by my conclusion/speculation that this menkyo was symbolic, and demonstrative of a special relationship between Takeda and Ueshiba.
Interesting that Takeda would be enraged at the sight of a fukuro shinai in the dojo, if he really taught/bequeathed YSR to Ueshiba. It is almost as if the possession of such a training implement would denote that Ueshiba was doing some study outside Tákeda's orbit - and given that a fukuro shinai and YSR are hand-in-glove, then this would support the idea that Takeda gave his student a symbol rather than a curriculum.