I think you are very right in that pre war Aikido is the budo Aikido and the post war aikido was influenced by the spiritual changes that occured to O'Sensei's life but apart from Yoshinkan what other styles preserved aikibudo? I think it is the only style out there that represents pre war aikido
Even within the Aikikai there were teachers that continued with the "prewar" flavor you speak of: Rinjiro Shirata, Bansen Tanaka, Morihiro Saito, Sadateru Arikawa etc. Even if Arikawa and Saito began training in aikido after the war, they had a harder, more combative style that you would never mistake for Kisshomaru's kind of aikido. And if you've ever seen a demo by Hiroshi Isoyama, then you'd know that there is nothing "pacifist" about it.
As Stan Pranin points out, Saito liked to point out the similarity between his waza and the waza of Osensei in the 1938 manual Budo as proof that he faithfully preserved the teachings of the founder. So the prewar/postwar dichotomy is too simplistic.