1938 Sc 515-518 Rescue of “North Pole-1” Station Scott 643-646

1938. Rescue of “North Pole-1” Station.
Catalog numbers: Scott 643-646, Standard Collection 515-518, Michel 614-617.
Issued on: June 21, 1938.
Perforation: comb11¾ x 12¼; line12¼.
Printing: Typography.
Colors: Multicolor.
Face value: 10 Russian kopek; 20 Russian kopek; 30 Russian kopek; 40 Russian kopek.
Quantity: 2,500,000; 3,000,000; 2,100,000; 1,500,000.