1938 Sc 483-486 North Pole Flight Expedition Scott 625-628

1938. North Pole Flight Expedition.
Catalogs: Scott 625-628, Standard Collection 483-486, Michel 584-587.
Issued on: February 25, 1938.
Perforation: comb12¼ x 11¾.
Printing: Lithography.
Face value: 10 Russian kopek; 20 Russian kopek; 40 Russian kopek; 80 Russian kopek.