Well, as luck would have it I'm running an F-model frontend and a drum rear on that Amen frame I'm doing, so if these are indeed for a CB750 they'd be perfect (assuming they look right with the rest of the bike). Obviously they won't stay red. Maybe I'll re bead-blast them and do a few black pinstripes or something.
So, no one's seen a set like these before? They aren't GS550 wheels because the star points don't cross (each GS point crosses like an "X").