I beleive Jim actually dichromate dips the alternators, this wouldn't be the right way to restore those clutch fins. The difficulty would be treating the two surfaces sepperately. The fins should be raw cast aluminum which could be accomplished a few different ways depending on the initial condition of the fins. The face plating could be done first, then coated with liquid rubber to protect it, then the fins restored, then remove the rubber and finallty, ink stamp date codes. PIA but could be done. The wrong color seal is the real detail issue IMO.