No. 16966. March 7, 1963. Thomas M. Vogt, St. Paul, Minn., made argument for petitioner; Felhaber, Larson Fenlon, St. Paul, Minn., with him on the brief. Hans J. Lehmann, Atty., N.L.R.B., Washington, D.C., made argument for respondent; Stuart Rothman, Gen. Counsel, Dominick L. Manoli, Associate Gen. Counsel, Marcel Mallet-Prevost, Asst. Gen. Counsel, and Melvin J. Welles, Atty., N.L.R.B., Washington, D.C., with him on the brief. Donald Savelkoul, Minneapolis, Minn., made argument for intervenor and