Peter A Goldsbury
I have discussed this in the columns I am writing. The iemoto (‰ÆŒ³) system became established for the transmission of traditional arts, but there is very little about this in English. After a few other candidates, M Ueshiba setled on Kisshomaru as his successor, but we do not know how he conceived of the 'structure' of the art, considered as a Japanese legal entity. The first thing Kisshomaru and Koichi Tohei did, after the Aikikai became more active, was to write technical manuals. Of course, in Budo Renshuu and Budo, there was a precedent for this, but these were never published for general distribution. Kisshomaru had his own ideas for the dissemination of aikido and Morihei Ueshiba seems to have accepted these, albeit reluctantly.
There's an interesting interview with Shoji Nishio here
in which Nishio stresses repeatedly that Ueshiba had exactly zero
interest in the management of any kind of organization.