The old paint codes were set up for either lacquer or enamel paints and are obsolete. Your best bet is to find a patch of original color on the car. The inside of the glove box door, firewall, or other surface that has been shielded from the sun and/weather can be used by a good shop to duplicate the color. They use an instrument that "reads" the sample and can produce a nearly perfect match. We use a modern color/clear coat finish on our cars. If properly done, will retain that "new" look for years.