I think it is similar to this 22-no-jo kata as taught by Yasuo Kobayashi Sensei. He also learned this kata from Tohei Sensei.
If you compare this to the 31-no-jo as taught by Saito Sensei, you will find many similarities.. one might conclude that the 22 (or 21) kata is essentially the same (with some slight differences, eg. choku tsuki in the 22 replaced by kaeshi-tsuki in the 31) as the 31 kata, just with different counting of the moves.
Since the 22 or 21 kata is similar to the 31, and Saito Sensei said the 31 came from Ueshiba Kaiso, then that must also be the source for the 21 (22) kata.
Here is Hiroaki Kobayashi Sensei demonstrating 22-no-jo..