Original oil and gas trade magazine vintage ad for THRONHILL-CRAVER COMPANY. Main office was located in Houston, TX. Unibolt Flow Manifolds make any Christmas Tree lighter, stronger, more economical. All connections are forged steel. Valves and chokes may be assembled in any desired type of manifold to best serve individual well requirements. This unique 1950 old petroleum oilfield industry equipment magazine advertisement would display beautifully matted and framed.