No. 74-1577. Argued and Submitted May 19, 1975. Decided April 12, 1976. Rehearing Denied May 14, 1976. Elinor Hadley Stillman, Atty., N.L.R.B., Washington, D.C. (William Watcher, Atty., N.L.R.B., and Peter G. Nash, Gen. Counsel, John S. Irving, Deputy Gen. Counsel, Patrick Hardin, Associate Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, N.L.R.B., Washington, D.C., on the brief), for petitioner. Mary T. Matthies, Tulsa, Okl. (Richard L. Barnes, of Kothe Nichols, Inc., Tulsa, Okl., on