Original oil and gas trade magazine vintage ad for ROCKWELL MANUFACTURING COMPANY of East Chicago, IN. Edward Valves, Inc. How To Stop Mud Valve Troubles on Drilling Rigs. Switch to Competitively Priced, Rockwell-Built Mudwonder Valves for All Mudline Services. Edward Valves, Inc, A Subsidiary of Rockwell Manufacturing Company. Unique 1955 petroleum oilfield drilling industry equipment magazine advertisement. On the reverse side are two fractional page ads for L-K PUMP VALVE COMPANY of Houston, TX. L-K Ball Bearing Wire Line Cat Line Swivels. And an ad for FAIRBANKS-MORSE. Unlimited Running Time for Your Pumping Engines. Motors, ZC Engines, Magnetos, Pumps, Diesels. Old 1955 petroleum oilfield pumping industry equipment magazine advertisements. Approximate page size 9 x 12 inches.