Your hub has dimples between the spokes which were only on K0 250/350 & K1 350. Academic really just for anoraks like me . Funnily enough the 1968 CB250SS (K0) in Dave Silver's museum has an incorrect hub for the year (see pic attached). His K0 is Sardine Blue and he got it from James May and it featured in James's 'Manlab' TV programme.thanks for the comments guys, the pictures were taken a couple of years ago, since then more has been done to her. Unfortunately i didn't have the hindsight to take pictures during the restoration, but i have a few taken before the work began and will post one of them up.