My japanese is not good enough, bought myself a nice book with very nice pic's but cannot scan these due to the construction of the book and do not want to ruine it.
Nice to know, they called it CB500R but in reality it was up to 749,35 cc, 86.7 rwhp at 11.000 rpm. Three valves and CDI ignition, dry clutch, dry sump.
Actually they went from 498 to 650, 675, 702 and finally 749,35cc over a timespan of 1972, '73 and '74.
Rob