Willy Ley, a German-American science writer, spaceflight advocate, and historian of science who helped popularize rocketry and spaceflight in both Germany and the United States, collaborated with the Monogram Model company in the 1950s to create a set of space vehicle models. Today’s ad from Boys’ Life magazine in 1960 highlights these sets. Each model included informational booklets on space travel written by Ley, and if you mailed a box end from a space model you could join up with the “Space Explorers”, complete with genuine membership card and an autographed photo of Mr. Ley himself.
Engineers' Dreams by Willy Ley is an excellent book and worth reading. Printed by the Viking Press in 1954.