When you find out, let me know
Seriously, I have 78 Comstars in my K3F project and I would like to have tubeless wheels eventually. From the research I done it looks like 1979 CB750 SuperSport used the same looking wheels, but made for tubeless tires. The way Honda makes parts, I would be inclined to believe that they are direct fit for 78 SuperSport.
Did you look into Gold Wings?
Edit: This is rear wheel for 79SS:
How modern do you want to go?