4, 50 Fr. dark bluish green with right attached blank field with printing machine number always with overprint "fortress Lorient" - this on the empty space inverted and additional a further inverted overprint over stamp and empty space going, unused with original gumming, printing with empty space only max. 10 pieces, as is probably the only one exists!, photo expertize autumn VP (2018) : "in the upper Perforation area of the stamp small thin affixed spot available, therefore as unused short attests. The other condition is perfect. " - very scarce variety the anyway rarely stamp with a printing from only 100 copies!