BELGIUM (1966) Surveyor. Weather balloon. Ministerial proof. Scott No B799, Yvert No 1393.
AVAILABLE AT $50
RUSSIA (2006) Base station*. Imperforate proof sheet of 25 stamps with color bars and printed title. Antarctic Exploration.
AVAILABLE AT $100
AUSTRIA (2022) 150th anniversary of North Pole expedition*. Black print of S/S.
AVAILABLE AT $15