Yes Mr Hill, open, questioning always have an answer
From that my point of view it is not esencial to have last video of any master technique because we havent achieved even that old way yet.
Any active master is continous working on its personal level of jutsu and do, so it is always changing and is only close followed by its contemporaries, I guess all his upgrades will pass down to students at determined time.
This is obviously not an excuse by any meanings to get stuck in old approaches or, in the case of writings Stevens Sensei would trust more on what you "recorded on your body"
during practise and thats to be smart. But also I have found and seen in some others "personal notes" on certain details and discovers as invaluable material.
"ok,but he would always warn me that what he was doing today, he'd be doing differently tomorrow."Hill
Thats also a way to say: hey, if you dare to sell this at least tell me, I deserve something
dont show something that is not anymore.
BTW the short films Ive got from renowed aikido professors is something I could never put on sale, they are little treasures just for personal and friendly use.
Manuel Chiquito Anderson