Phil, perhaps you've heard of Bob Jameson and Bob Hansen. Some information on these two mens' involvement with the CB750 beginning 1967, can be found in the website under the "2009 Meet" section.
Bob Hansen sent Bob Jameson and Bob Young to Japan in 1968. At the 2009 meet, a number of us SOOC members met personally Bob Jameson (then age 80) and Bob Hansen (then age 90.) Bob Hansen's association with Honda began 1959. Bob H was invited to visit Honda Japan in 1967 and during his visit, while at dinner, gave Sochiro Honda the idea to build a 4 cyl, not a 650cc 2 cyl as was being planned.
While in Japan, during March 1969, Bob Jameson watched and was present when the #1 machine was built, not on an assembly line, but on the floor by a very excited group of Japanese engineers. Bob J was in Japan for more than 30 days, test rode the #1 bike (among others.) Bob J had very interesting stories of seeing the manufacture of parts and the building of motorcycles following the #1 CB750. I've not had the privilege of meeting Bob Young who was in Japan during that period for over 6 months.
Somewhere in the website and/or on youtube, there is a link to the one hour presentation these men gave on Friday, Saturday and Sunday of the meet.
I talked with with Bob Jameson and Bob Hansen as much as i could over the 3 days of the meet. They both said every CB750 was built in Japan, not in the USA.
That steering damper gusseting is certainly interesting, it's on a number of members early vins.
