Hi, In your experiences would gray bottom pickups in a July 64 Jazz Bass be identical in construction to a black bottom pickup that preceded it (other than color) taking into consideration expected variation from pickup to pickup owing to hand winding. I believe they were still hand wound until 1965 with the same magnet type and enamel insulation but correct me if I'm wrong. I am aware Fender currently produces 1962 and a 1964 jazz bass reissue pickups. Why would that be then? Thanks,