Nos. 9869-72, in court of appeals for 3d circuit, William L. Mellon, jr., and Mellon National Bank and Trust Company, etc., v. commissioner of internal revenue; Mathew T. Mellon and Mellon National Bank and Trust Company, etc., v. [same]; John F. Walton, jr., and Mellon National Bank and Trust Company, etc., v. [same]; Mellon National Bank and Trust Cobpany, etc., v. [same], on petition for review of decisions of Tax Court, brief for respondent.