1976, Penrhyn. 200 years of independence of the United States of America. Collective, progressive proof (9 phases) for the stamps of the souvenir sheets (2 strips of 3), for the souvenir sheets frame, and for 2 labels of the print sheet. Printed together on one sheet each. Some printer's notes. MNH. Some small paper wrinkles. In all 18 proof strips of 3 (= 54 proof stamps), 9 proof s/s frames, and 18 proof labels. In this form UNIQUE.