Nos. 95-3407 and 95-3641 ARGUED SEPTEMBER 4, 1996 DECIDED FEBRUARY 21, 1997 Michael L. Einterz (argued), Indianapolis, IN, for Dilling Mechanical Contractors, Inc. Aileen A. Armstrong, Peter D. Winkler, Vincent Falvo (argued), National Labor Relations Board, Appellate Court, Enforcement Litigation, Washington, DC, Walter Steele, National Labor Relations Board, Indianapolis, IN, for National Labor Relations Board. William R. Groth, Fillenwarth, Dennerline, Groth Towe, Indianapolis, IN, for Indiana