Which instructor(s) at Aikikai Hombu Dojo have made the biggest influence on Moriteru Ueshiba's technique?
Doshu steps forward on ushiro techniques;
At the end of shihonage one hand grasps and the other pushes the hand towards the wrist (as in kotegaeshi);
In iriminage ukes head is brought to tori's shoulder;
to name a few.
My references are his classes at summer camp and the book Best Aikido