The picture I posted was taken in 1936, as part of the Noma Dojo series of photographs. According this article
by Fumiaki Shishida:
in 1928, Ueshiba changed the name of his martial arts school to Aioi-ryu Aiki Bujutsu. He again renamed his school Aiki-Budo or Ko-Budo, and finally settled with aikido in 1942.
Reading Nidai Doshu's writings about the early years of his father reveals that O-Sensei trained in Kito-ryu (one of the antecedent arts of judo) and judo itself, prior to training in Daito-Ryu. Words in parenthesis are mine..
From: The Life of O-Sensei in Aikido Online
...In 1901 when he was 18, the Founder took the first steps in the direction of achieving his driving ambition. He had come to Tokyo because he wanted to be a great merchant. He spent busy days working on a wholesale street, and studied jujutsu of the Kito Ryu at night. ...
(after service in the army, O-Sensei was asked to re-enlist and enter the military academy, but he turned down the offer.)
...Although he refused to enter the academy, he did not want to return to an ordinary life. Therefore the vigorous and spirited young man became a community leader in his village of Tanabe and managed the activities of his district. Kiyoichi Takagi, then just a third grade holder in judo, visited the Founder's hometown. The Founder put together a group at the Young Men's Club of the town and had Takagi teach. Takagi later became a judo 9th dan holder. The Founder himself studied judo with great diligence.
IMHO, I think ne-waza should also be included in training in the event that the conflict goes to the ground. At least the historical record shows that O-Sensei did train in ne-waza.