1 Fr. special stamp "soldiers" with overprint in type I, variety "inverted overprint", correctly franked single franking on cover from "Ghyvelde 10. 7. 40" to Dunkerque with arrival postmark on the back from 11. 7. 40, photo expertize Lothar autumn VP (2016) : "the condition is perfect. These stamps are only in very small number of pieces recorded, so that they very rare are. Inverted overprints on special stamps are extremely rare. "