Two stage paints (base coat - clear coat) were not used in 1952. The exterior paints were a synthetic (alkyd) enamel (Dupont Dulux) but repaints and repairs were often done in Dupont Duco (a quick drying and durable lacquer).
A modern acrylic enamel (with or without a hardener) or a single-stage two-part urethane are modern equivalents.
