Francis X. (Frank) Baur Jr., a production executive and assistant director, died July 3 of pulmonary fibrosis at Ojai Valley Community Hospital. He was 75.Baur began his film career in the mailroom of Paramount Pictures in 1936. Following his service as a pilot during WWII, Baur returned to Par in 1945, working in the budgeting department. He transferred to the production side and worked as a second assistant director on numerous features, including “The Greatest Show on Earth.” He segued into television in the early 1950s, serving as a first assistant director on “Hopalong Cassidy.” In 1955 he joined Four Star Films, where within eight months he had been upped to VP and exec production manager for all TV production. Baur subsequently returned to feature work, where he served as a production manager and, in recent years, as associate producer. Baur is survived by his wife, Germaine, daughter of the late Hollywood director George Marshall; and daughters Geri, a TV segment producer, and Christine, a stunt coordinator. Funeral services will be held today, 11 a.m. at the Corpus Christi Church in Pacific Palisades. Family requests that in lieu of flowers, donations may be made to the American Lung Association.