No. 55, Docket 73-1148. Argued October 31, 1973. Decided December 28, 1973. John Ferguson, Atty., National Labor Relations Board (Peter G. Nash, Gen. Counsel, John S. Irving, Deputy Gen. Counsel, Patrick Hardin, Associate Gen. Counsel, Elliott Moore, Asst. Gen. Counsel, Alan D. Cirker and Ken J. Hipp, Attys., Washington, D.C., on the brief), for petitioner. Mozart G. Ratner, Washington, D.C. (Ratner Driesen, Plato E. Papps, Washington, D.C., on the brief), for intervenor. Joseph C. Wells, Washington