Officials of Teamsters International Union preview special 48-page "Labor Day 1970" Rotogravure Supplement appearing in today's Boston Sunday Herald Traveler, the largest such section printed by a major newspaper in the United States. Nicholas P. Morrissey, president of 60,000-member Teamsters Joint Council No. 10 in New England and the union's regional organizer, is flanked by Ralph J. Gilman, secretary-treasurer and business agent of Local 122, Boston (at left) and Gerald F. Gross, trustee-business representative of Local 653, Brockton (at right).