O-sensei's ken was O-sensei's ken. Respected kenjutsuka considered it "unique" and/or "interesting." (Read between the lines folks, these are Japanese.) Yet, Ueshiba had very respected Kenjutsuka as both students and friends. There was respect born of pragmatism there regardless of how "unique and "interesting" his ken was!
Shirata sensei was Saito sensei's sempai by many years. He studied with O-sensei when Ueshiba was teaching weapons in the context of combat and when famous kenjutsuka frequented the Kobukan. He (Shirata) also taught in his teacher's stead at that time and had real combat experience as well. Later his (Shirata's) ken was recognized by kenjutsuka as the "real deal." Still, Shirata sensei traveled with some regularity to Iwama to train with Saito sensei and his students. This is as much a testament to Shirata sensei's humility and sincerity of purpose as it is to his respect for Saito sensei's dedication to their mutual teacher and his (Saito's) seriousness of purpose and accomplishment.
Shirata sensei was head of the Tohoku Region but had no problem with the influence and teaching of Saito sensei in that region as well. I gather there was mutual respect between the two men despite their difference in years. Due to this relationship, while studying with Shirata sensei I, and I believe most others studying in the region, learned many of Saito sensei's weapons forms. Nevertheless, Shirata's and Saito's weapons usage were qualitatively different from each other, also, Shirata's curriculum of instruction was not at all limited to the plentiful curriculum that Saito sensei taught.
With that in mind here is something important to consider. Shirata sensei taught exercises to develop "internal strength" and "Aiki" (two distinct but related things.) He also was capable of teaching jujutsu from pre-war Judo, to Daito ryu jujutsu to modern Aikido and did, to various students. What we see in his recently released videos is NOT in my experience his teaching of "pre-war Aikibudo. He was perfectly capable of teaching the entire contents of Budo Renshu and Budo, and did, and more. What is on those videos is NOT that . . . obviously. Although it might not be seen as modern Aikido as well either, at least not to those that asked for that video not to be released.
Anyway, the teaching of the exercises to develop "internal strength" and Aiki was not Shirata sensei's original contribution. They were exercises passed on from his teacher, from his teacher's teacher. The teaching of the jujutsu curriculum was not Shirata sensei's original contribution either, they too were passed on from his teacher, and his teacher's teacher. (How else could they be later recognized as Daito Ryu by those that practice and/or taught Daito Ryu?)
Among Shirata sensei's original contributions were his exercises that bridged between the exercises to develop "internal strength" and Aiki (taught by his teacher) and the jujutsu (taught by his teacher.)
And then again another of Shirata sensei's original contributions were his Ken exercises (some directly reflective of the empty handed exercises) meant as a bridge from "internal strength" and Aiki to Kenjutsu. (There are Jo exercises too.) What you see on the video is NOT pre-war kenjutsu. Anyone with a knowledge of kenjutsu will (and do) immediately recognize that. As a well educated budoka, Shirata sensei naturally knew that. (The technical/tactical considerations necessary for kenjutsu were taught separately.)
It is common knowledge that Ueshiba sensei took kenjutsu kata (likely the omote forms, although he had close friends and a teacher "in the know" and probably not unwilling to exchange ideas in private) of several koryu and applied Aiki to them creating something "unique" and "interesting" but undeniably effective . . . for him! (Not necessarily for thousands in pajamas waving pieces of wood about. It is wise to know one's limitations!)
If history serves as any sort of teacher it indicates to me that if one wishes to "do" jujutsu one must learn to do jujutsu, the same applies for kenjutsu, jojutsu, yari, naginata, tanto, etc. If one wishes to "do" ("be" is probably more appropriate really) Aiki anything, one must first learn to "do ("be") "internal strength" and Aiki.
Only the joining of a real (proven tactical/technically proven) combat practice and real (readily proven effective, compelling and irresistible) Aiki will produce an Aiki combat practice. It logically follows that the same is true for a spiritual practice.
As historically important as video is, none of this is likely to come from a video. One is more likely to win the lottery I suppose. When the thread of transmission is broken it is likely broken for a long, long time.* If the thread is in tact, that fact will be evidenced through works not just words . . . just as O-sensei did.
All evidence points to O-sensei's weapons forms, tactics and techniques as NOT being what gained him respect from the weapon aficionados of the period. It was his real application of Aiki within the realm of that venue that won him the hard earned respect of those that knew better than most do today. And we shouldn't be surprised that this would be so. After all his art was called Aikido!
*This is because these (both Aiki and proven combat practice, but even more so for Aiki because it is so UN-natural) are an accumulation of rare discoveries synergistically combined to form a unique result. (It isn't natural in the sense of being commonly present, which is why those several authorities of accomplished in ancient traditions (koryu) recognized what they experienced as "unique" and "interesting" and some were compelled (despite of the, what must have been keenly felt and almost certainly present, disapproval of their peers) to try to uncover roots of that effective uniqueness.
One possible example is a computer. A computer is an accumulation of rare discoveries (over centuries) synergistically combined to form a unique result. If we were all transported to the dark ages, it is unlikely that anyone would "discover" on their own, or even within a generation, how to reproduce a computer in the same manner that Newton "discovered" gravity.