No. 80-1494. Argued February 4, 1981. Decided May 12, 1981. Warren M. Davison, Baltimore, Md. (Earle K. Shawe, Leslie R. Stellman, Stephen D. Shawe, Shawe Rosenthal, Baltimore, Md., on brief), for petitioner. Susan L. Williams, N.L.R.B., Washington, D.C. (William A. Lubbers, Gen. Counsel, John E. Higgins, Jr., Deputy Gen. Counsel, Robert E. Allen, Acting Associate Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, William R. Stewart, Deputy Asst. Gen. Counsel, Washington, D.C., on brief)