@chrisr I realize your comment is six months old, and I never saw it until today. Those look like Showa 27mm forks. I have a nice set with trees, boots and races sitting on a shelf. I've seen rebuild components, but there is not a single O ring or seal from back in the day that is not still produced. I've rebuilt several vintage shocks and forks by sizing.
Measure the tube diameter to double check. Also, Franks Forks has a nice list of fork sizes used throughout the years, and Honda used those 27mm forks from 1967 to 2003 in everything from a CT90 to XR70,80, 100, etc.