Dan or anybody, what was the Katori connection? I am aware that O Sensei had a high-level Yagyu Shinkage ryu swordsman train with him, and he sent Kisshomaru to train in Kashima Shinto ryu. I am not sure if I've read anything tangible about a connection to Tenshin Shoden Katori Shinto ryu.
Yoshino Sugino and Minoru Mochizuki were both pre-war Ueshiba and Katori students. I have no idea how much Ueshiba watched or absorbed (if anything at all).
I'd also note that Kiyoshi Nakakura had a kendo group going at the Kobukan while he was there.