cover 10Kr. blue (Type IV), affixed to undated envelope (part of reverse missing) registered to Sillien and tied by "ILLAVA" c.d.s. (4.1), reverse showing "ZSOLNA" c.d.s. (5.1)

细节
cover 10Kr. blue (Type IV), affixed to undated envelope (part of reverse missing) registered to Sillien and tied by "ILLAVA" c.d.s. (4.1), reverse showing "ZSOLNA" c.d.s. (5.1)