No. 71-2767. June 12, 1972. Timothy H. Fine (argued), G. Joseph Bertain, Jr., San Francisco, Cal., for petitioners. Joseph C. Thackery (argued), William F. Wachter, Marcel Mallet-Prevost, Asst. Gen. Counsel, Peter G. Nash, Gen. Counsel, Ogden W. Fields, Executive Secretary, N.L.R.B., Washington, D.C., Roy O. Hoffman, Reg. Dir., Jerrold C. Schaefer, San Francisco, Cal., for respondent. R. Barry Churton (argued), of Cooper, White Cooper, San Francisco, Cal., Garret McEnerney, II, San Francisco, Cal