Kasimir Bileski (September 14, 1908 - January 19, 2005) was a noted Canadian philatelist and stamp dealer based in Winnipeg, Manitoba, Canada. He is best known for his discovery and promotion of the famous "Seaway Inverted" stamps of 1959. 

He was also involved in the holding of many of Canada's rare stamps, and wrote widely on philatelic issues.

James Joseph Mattern (March 8, 1905 – December 17, 1988) was an American aviator. Mattern undertook a number of aviation world records, including twice attempting to break the world record for aerial circumnavigation set by Wiley Post and Harold Gatty. Both attempts failed; the second in 1933 resulted in a crash landing and subsequent rescue by Eskimos and Sigizmund Levanevsky in Siberia. In a twist of fate, Mattern would join the search for Levanevsky after he went missing in 1937. Levanevsky was never found.

In 1928, Mattern sold an air plane to an oil company in Texas owned by Michael Benedum.Benedum would later become a frequent financial backer of Mattern's flying activities. In 1937, Mattern was hired as the aeronautical director for the Benedum and Tree's oil company.

Starting in 1938, Mattern was a Lockheed test pilot on the P-38 Lightning and during the war helped develop the 'Piggyback' two-seat version that significantly reduced training accidents. In 1946 he was diagnosed at the Mayo Clinic with a ruptured blood vessel in his brain (perhaps due to repeated excessive G-forces experienced while demonstrating P-38s) and was unable to fly again because of the condition. After losing his ability to fly, Mattern and his wife became real estate brokers and then operated a travel agency. He also supported the space program, attended three Apollo launches and had his pilot's license carried to the moon aboard Apollo 11. He also marketed aviation calculators known as the Mattern computer, a course and mileage slide rule, in the late 1940s.