I am only going to explain the 4 bolt fork thing one more time. The (center part # 970) kits produced in 1970-1971...did not have fork legs with 4 bolt lowers. Look at cover on Cycle magazine Oct 1970 at the parts lay-ed out, not the bike in background as that is not an CR750 but the works RC750 Factory bike.
When Honda came back to Daytona in 1973 with Steve M, Sumiya and Roger Riemen as riders, they also introduced KIT fork assemblies with 4 bolt lower legs and had the center part number of "971". They also intruded the smaller alternator assemble with a smaller cover with new center part number of "971"
But, for you that are unaware...these 971 kit forks were not the same as the 4 bolt lowers used on RC750 Mann factory bikes.
I have all documentation and pictures along with having ownership of of one of these fork assemblies.
Mark @ M3