Deloor was professional from 1932 until 1939 when World War II caused the end of his career. Deloor was serving in the Belgian army at Fort Eben-Emael near Maastricht when the German army invaded the fort on 10 May 1940, but Deloor together with some 1,200 Belgians were taken prisoner. In Stalag II-B or the prisoner-of-war camp II-B, Deloor was able to work in the kitchen due to a German officer that was interested in sports. When Deloor returned from the war, he came back to a plundered house and decided to start a new life in the United States of America in 1949. After ten years in New York he moved to Los Angeles. He worked as a mechanic until, in 1956, an affluent client helped him find a job at Cape Canaveral aerospace centre. Here he worked for the Marquardt Corporation, the aeronautical engineering firm, in the development and design of the ramjet engine for NASA that was used on the Apollo 11 Saturn V rocket.^[2] He lost his first wife in 1966 but remarried. In 1980, Deloor returned to Belgium.^[3]

• Gustaaf Deloor at Cycling Archives
• Official Tour de France results for Gustaaf Deloor^{[permanent dead link]}