The original paint was probably nitrocellulose lacquer. They don't make that anymore. Acrylic lacquer is still available, but limited supply, i.e. pre-packaged colors, nothing that can be custom made. A paint similar to the old school lacquer would be acrylic enamel, but that isn't great at all.... tell him to go with single stage urethane. It will be more durable, cost effective, and shine longer.
Dakazman