Re: Where did O-Sensei get his sword training?
Taken as a sincere question. The answer, given sincerely, is that I know it. But, when the question turns to the aikido crowd ... do we know it? Mostly, no.
There are videos of Ueshiba with a sword in hand. There are interviews about Ueshiba's weapons work. Stan has tons of reference material. Watch Ueshiba. Then sit and watch as many koryu kenjutsu demonstrations as you can. Youtube has a lot. Do you notice anything similar between Ueshiba and koryu?
Now, who was training koryu sword? Kisshomaru was. What were the conversations like afterwards? His father said, You would do it this way with aiki.
Takeda was known to switch hands when holding a bokken. Ueshiba did, too. Takeda worked with weapons, including the sword. It would be silly not to think that Takeda taught Ueshiba something of the sword. We do know that Takeda taught Ueshiba aiki.
Finally, Ellis Amdur's Hidden in Plain Sight. While Ueshiba "learned" some koryu kenjutsu, it was never complete nor did Ueshiba keep to the koryu model. Instead, Ueshiba took out bits and pieces of what he wanted, used aiki to infuse them with power, and then either practiced them or taught them to a few select people.
And even though it grates on people, the answer is still -- pretty much all the martial skills and abilities about Ueshiba can be traced back to Takeda. Ueshiba *was* a Daito ryu man, through and through. From Takeda to Sagawa to Horikawa to Ueshiba, they all talked about the same things. Just because Ueshiba took some of the spiritual stuff a bit farther than the rest, doesn't mean Ueshiba created something "new". He did exactly like Sagawa and Horikawa did ... they all said they went in different directions from their teacher.