Nos. 91-2638, 91-2663. Argued March 3, 1992. Decided June 2, 1992. Henry Jared Wallace, Jr., Reed, Smith, Shaw McClay, Pittsburgh, Pa., argued (Lauren Klett Kroeger, on brief), for petitioner. Margaret Gaines Bezou, N.L.R.B., Washington, D.C., argued (Jerry M. Hunter, Gen. Counsel, D. Randall Frye, Acting Deputy Gen. Counsel, Aileen A. Armstrong, Deputy Associate Gen. Counsel, Howard E. Perlstein, Supervisory Atty., on brief), for respondent. Petition for review from the National Labor Relations