That is pretty standard for Hondas and chondas Mark, but it takes a lot of time and work to bring them to that stage of wear. The nominal piston skirt diameter when it leaves the factory is 63.985 mm, so yours have no measurable wear, it's just that one of them is scratched. I'd replace the rings, certainly re-use the clean piston, and look at linishing or buffing the scratched one to smooth it out a bit - mostly, remove the raised-up edges of the scratches.
