To add to Dan's questions one of my own.....all of these guys Dan refers to (Ueshiba, Shirata, Shioda, Mochizuki, Tomiki, and later Tohei and Saotome) how do they continue to have the abilities they exhibited at age? I don't think it was youthful speed, timing and the like. I am 70 and can still lift considerable amount of weight...I still go to the gym to keep the body working.....but I no longer turn, spin and the like as I once did.....technique isn't going to hold me over now and to continue to rely only on the outer form just won't do.....I don't think it did for these gentlemen either......
Well, specifically regarding the Founder, check out the interview with Gaku Homa earlier in this thread. Regarding the others, and this is just a guess, they may have been taking private classes from Dan.