In his autobiography, Gene Wilder says that John Wayne was offered the part that was eventually played by Harrison Ford. Wayne loved the role and was eager to work with Wilder. However, an agent tried to offer Wayne less than his usual fee and the legendary actor turned the film down. This may be true, but it is actually unlikely. By 1979, Wayne was too ill with stomach cancer to consider film work, and he died later that year from the disease.
Some viewers have complained that the name Darryl is anachronistic. One etymology source says that, as a first name, it was not used by English speakers until the late nineteenth century. However, the name comes from Old French "d'Airelle", meaning someone from the town of Airelle in France. Airelle itself means "open space", from the Latin, so it might be quite old.