I ran across "The Secret Teachings of Self Defense" some time ago. It is a nice document with some history. Some points to discuss perhaps.
The author claims to be the 19th successor of the Yagiu Shingan School and the 13th successor of the Yamato School. Now, Ueshiba did study Yagu Shingan ryu but did not advance very far. As to the name Yamato ryu, this is the "old" name of Daito ryu. (older style kanji pronunciation - somewhat)
Most of the technique are better line drawings (but less artistic) from the famous hand drawn "Budo Renshu" by Miss Takako Kunigoshi (1933) of which there have been recent reprints. One of it's titles was the "Secrets of Aikijujutsu".There is also a small amount of techniques reminiscent of Hakko ryu (a Daito ryu spin off).
The jo or hanbo (stick) work is supposed from the Taketa School by Mr. Ichi -- this I think is from the Takeda ryu spin off from Hakko ryu and other arts founded with a Oba (Ichio) Sachiyuki involved in its mid-20th century lineage.
The last has a section called "Kempo of Yamato School (another name Karate) and shows the form of Teranomidare. I started a look at Karate forms similar because the moves are ‘generic' Okinawan techniques strung together. Maybe a karateka will recognize it. There is however an aikikempo section of Daito ryu -- the late Yukiyoshi Sagawa printed a rare small flyer on this aspect of the art (looks like Daito ryu locks with some more punches & kicks thrown in.)
I contacted the Gardena Judo dojo, one of the oldest dojo in Southern California but all the old timers have passed away. Supposedly either the daughter of the author or the translator (I think that one) is still alive. The translator Tsuke Hagio was, at the time this was published, a godan in Kodokan Judo.
The Hawaii Karate Museum was the first to post this online and can be seen at http://museum.hikari.us/
(1950's) where they comment the karate is "based upon Kenwa Mabuni's Seipai No Kenkyu Goshinjutsu Hiden (October 25, 1934)."
This is freely available on the net and is a fine manual to own (now if people would only start doing some of the old Aikibudo stuff…..)