Scott C6 1923 24c Biplane Airmail Issue Mint Graded XF 90J NH with PSE CERT Updated on September 17, 2023 By admin Comments Off Certificate states: it is genuine unused, o. American Philatelic Society Member #178998. Share Tweet By admin You May Also Like US Scott #C3 Mint NH XF Extra Fine Scott C5 16 Cents Propeller MNH Nice Stamp SCV $120.00