Nos. 91-1964, 91-2146. Argued December 6, 1991. Decided May 26, 1992. Michael S. Mitchell, Stephen P. Beiser (argued), McGlinchey, Stafford, Cellini Lang, New Orleans, La., for Missouri Portland Cement Co. Jerry Hunter, Lisa N. Richardson (argued), N.L.R.B., Contempt Litigation Branch, Aileen A. Armstrong, Linda J. Dreeben, N.L.R.B., Appellate Court, Enforcement Litigation, Washington, D.C., Joseph H. Solien, N.L.R.B., Region 14, St. Louis, Mo., for N.L.R.B. Petition for review from the National