Nope, here is the answer I am looking for.
Mr. Honda, in his reply to a question from an engineer, explained Honda's objectives in developing the CB750 in the January 1969 issue of the company newsletter (No. 124):
"When I went to Switzerland last June," he said, "a policemen on a white police motorcycle came into the park where we were. He then got off his bike. I was watching it, thinking what a small motorcycle he was riding. I was amazed to find it was a Triumph 750 cc. So, actually the motorcycle was fairly big, but it looked small since the policeman was so big. [Laughs] I knew then that our bikes wouldn't sell in foreign markets if we kept building them according to our Japanese perceptions. That's why I suddenly became enthusiastic about this, and it's why I started telling them to develop a bigger model as soon as possible."