Czechoslovakia 1918 Hradcany 25h imperf proof block of 4 in blue doubly printed with Windhover 2h inverted in green, on ungummed buff paper, as SG 8 & N24
Czechoslovakia 1918 Hradcany 25h imperf proof block of 4 in blue doubly printed with Windhover 2h inverted in green, on ungummed buff paper, as SG 8 & N24