Original oil and gas trade magazine vintage ad for GEOPHYSICAL SERVICE INC. Main office and factory was located at 6000 Lemmon Avenue. Dallas, TX. Pictured is Mr. Curtis H. Johnson, manager of the Marine Division. GSI organized to serve in offshore exploration. Personalized service assures efficient attention to your problems. This unique 1953 old off-shore petroleum exploration magazine advertisement would display beautifully matted and framed. Nice graphics.