Mr. Amir - Thanks for your response. I'm fascinated with Hirai sensei, in part for the prestige he had and also for his apparent ability to negotiate the politics of association with Ueshiba Morihei so well.
There are quite a lot of videos of Takenouchi-ryu, this being one
And here is Hirai sensei's Korindo
(one of four) - I chose this, even though it's blurry, so that one can actually see HIrai sensei. I really do not see much similarity, except in the most general sense that both are doing Japanese martial arts.
I've read through some prewar lists of schools enrolled in the Butokukai as well as skimmed Martial Arts and the Body Politic in Meiji Japan (where neither aikido nor Daito-ryu is not mentioned). There was a jujutsu section, going back to the very beginnings of the Butokukai and many ryu were involved - it was, not surprisingly, dominated by judo. There was certainly no conflict between the various ryu whose name would be used, contrary to my previous understanding of this account.
It seems clear that the account that all grappling schools were subsumed under the rubric of aikido is incorrect. Rather, aikibudo was important enough (Tojo Hideki, Prince Konoye, and innumerable generals, admirals and politicians were involved) that they had to have a place for it in the Butokukai. They changed the name to aikido to fit with the other sections (judo, kendo, etc) - rather than something significant to the larger budo world, it was a minor administrative entry of one martial art into their membership.