500th Anniversary (in 1973) of Nicolaus Copernicus 1974-1977
Regular and Airmail Stamps (May 24, 1974)
Sc 680 / YT 743
Sc 681 / YT 744
Sc C415 / YT PA530
Sc C416 / YT PA531
Sc C417 / YT PA532
Sc C418 / YT PA533
Sc C419 / YT PA534
Souvenir Sheet (May 24, 1974)
Sc C420 / YT BF40
Surcharge (1976)
Sc 695 / YT 750A
Sc C444 / YT PA550
50th Anniversary of Linderbergh’s Solo Transatlantic Flight from New York to Paris 1977 (July 6, 1977)
Sc C460 / YT PA561
Sc C461 / YT PA562
Sc C462 / YT PA563
Sc C463 / YT PA564