Original oil and gas trade magazine vintage ad for NATIONAL TANK COMPANY of Tulsa, OK. National Separators, National Tanks Wish to Express Our Sincere Appreciation for the Part You Have Had In Making 1930 Our Most Successful Year. This We Attribute to you Appreciation of Dependable Performance. This unique 1930 dated oilfield petroleum well equipment magazine advertisement would display fantastic matted and framed. Great graphics. Art deco. Minor crease on the top of ad.