I find your comments very interesting, even if I don't totally agree with all of them.
Just out of interest, have you taken ukemi from either Seigo Yamaguchi or Gozo Shioda? I didn't meet the latter, but I did have experience receiving Yamaguchi Sensei and what I felt from him I would classify according to my current understanding as "internal" power. One illustration of this is that when he applied nikyo to me I didn't feel at all what I expected: I felt a surge of something (let's call it "power") and lost all my strength. No-one else has given me this feeling. I have heard first-hand accounts of Shioda Sensei which suggest that his aikido too had this effect. Perhaps we simply disagree on what is "internal" and what is "external".
What I do agree with is what you say about "body organisation". No aikido teacher I have come across has ever taught this explicitly, and any skill I have in this comes from my yoga training. Many aikido teachers talk about "correct" posture, and some (including Hiroshi Ikeda and my own teacher, Minoru Kanetsuka) have certainly practised and demonstrated postural exercises that I understand to be aimed at developing internal structural organisation, but none has in my experience taught these coherently, explaining what their purposes and effects are. Nor have I seen an aikido teacher talk about the "frame" or the function of skeletal alignment.
Alex, thank you for your kind words. One of the great sorrows of my martial arts life is that I never got to train with Yamaguchi Sensei. I have only seen films of him and he looked exquisite. (Also, if I understood Gleason Sensei correctly, he studied Itto ryu)
As alays there is the epistemological problem in that there are a lot of people I've never worked with. But in fifty years there are a lot I have. I think relevant to this discussion is that my teacher for some years, Saotome Sensei first began aikido under Yamaguchi Sensie (or so I believe). I would unhesitatingly extend my comments to Saotome Sensei. He can be exquisite, but I don't think he does techniques in the internal camp. Ikeda sensei is doing some serious investigations into the internal, but, I am pretty sure thay are am import, and I'm pretty sure where they came from.
Part of the problem is that there is an andragogy for teaching the internal, and it is found in Xing Yi, Ba Gua, or Tai Chi. It is every difficult to bring in concepts that can be "spot" applied into another martial art. Perhaps not impossible, but difficult. In my opinion, many of the cannon of aikido techniques have postures that get in the way, so one would have to change kihon to a large extent. Ikeda Sensei has not done that yet, but without someone doing it I'm not sure the grafting of the internal onto aikido will be successful. Another way of stating this is to ask the question, if you want the internal so badly, why study it second hand.
Of course there are those that claim it was always there and they they are rediscovering it. Who am I do say, and I intentionally restricted my comments to an extrapolation from those people I have worked with. Again, there are a lot of people I haven't worked with, but there are a lot I have, and just because someone does something you don't understand doesn't necessary imply one technology or the other.
In any case, regardless of whether this sort of investigation is an import or a native son, it is all healthy and good and probably rises all boats. Again, thank you for your kind worlds