25 C. Postal stamp \"Merkur head\" blackish opal green, block of four from left margin of sheet with two vertical overprint \"Occupied area North France\" in type I, prefolded, unused with original gum, mould stain were removed but are still slightly visible, otherwise impeccable, very scarce unit, particularly since in unused condition there most on cover were used there, signed, expertise Lothar Herbst VP (2023), Michel 2.400.-