I had the pleasure of being present both at both Shirata sensei's house and in his office at the Budokan (I thought my head was going to go through the wall in that three tatami area! But Shirata sensei l dropped me like a stone and landed me like a feather!) when Shirata sensei went over Budo from cover to cover to aid Prof. Stevens' translation of Budo.
You have to understand that Shirata sensei may have said something like, "That's elbow power." with the addition of a gesture and left it at that as we trained in that sort of thing regularly.
If one were to translate the book Budo or Budo Renshu more or less literally it leaves questions about referents unanswered (remember that those books were intended for O-sensei's students not for a general audience.) If one were to translate the book Budo or Budo Renshu with detailed explanation the books would necessarily be much, much larger and that would still assume that the translator knew what O-sensei's original intent and interpretations were . . . which, ironically, almost always leads one into areas of much contestation and acrimony.
BTW, Kuden is often used to cover those areas that the author decides CAN NOT be adequately described in a written format. The implication (previous to telephony etc.) was that if you could tell a student you could show them as well AND test that they understood what you intended to communicate.
So there you go again, another circle back to "It has to be felt." Once everyone is "on the same page" then cryptic communication found in densho and the like can be effectively used . . . even then the stuff dies out though. Many Koryu are proof enough of that.
All the best,
I don't have the answer, but I know where you might be able to find out. The English version of Budo was translated by John Stevens and while translating it, he often visited and got help on the book from his teacher, Rinjiro Shirata. Shirata Sensei was a student to and an assistant instructor for Morihei Ueshiba during the time the book was put together. Undoubtably John Stevens asked Rinjiro Shirata about that sentence.
I understand that Prof. Stevens occasionally does seminars on the east coast. (Ron would be the one to ask about that.) If you ask him, I am sure he would give you a straight answer.