Original vintage oil and gas magazine ad BIGNALL & KEELER MACHINE WORKS, of the N. O. NELSON MANUFACTURING CO., of Edwardsville, IL. Pictured is: the No. 20 Duplex machine with a hole 23 1/2 inches in diameter through the arbor and die head, and will handle pipe and casting from 10 to 20 inches inclusive. It is said to be the largest in the Oklahoma oil fields and is located at Wewoka. Peerless, Duplex, B&K, P.D.Q.C. Old 1928 petroleum drilling advertisement. Would look sensational matted and framed!