The mokuju is sixty-five inches. 166 centimeters. A jo is 48 inches - 122 centimeters.Ueshiba's teaching of jukenjutsu was all prewar - he did not do so post-war.
Furthermore, prewar, O-sensei used a bo, according to Ueshiba KIsshomaru and according to his pre-war student, Iwata Norikazu, who maintained his aikibo practice until his last days.
Ueshiba awarded Hikitzuchi Michio a menkyo in aikibo - a complete e-makimono.
The use of the jo was, by best evidence, post-war. One contradiction that might be made is the jo of Shirata Rinjiro. However, Shirata sensei adopted the external forms of Saito Morihiro, despite the latter being his junior by over a decade - and within those forms, he 'inputed' his own understanding - prewar Daito-ryu.
, which apparently Takeda Sokaku DID teach Ueshiba back in 1921, is still in existence and radically different from what Ueshiba did with his 'makura-yari' (the short spear replica that he used, which was, in fact, an enactment of Kagura-mae (ritual Shinto dance), For more information on this last point, HERE