South Vietnam, 100 Years World Organization for Meteorology, March 23rd, 1973, Michel Nr. SVN 525; A single stamp with a 1D nominal ws issued in perforation 12.5:12.
Mint block of four of which the top right stamp shows a printing flaw in the shape of a white spot on the earth’s surface.
Detailed scan of the affected area
This stamp was not officially released imperforate, however, a small number of imperforate trial proofs have come to market.
Enpreuve de Luxe; printed on cardboard paper
Registration Nr. 201270