1 Fr. Charity issue "exhibition - the overseas France 1940" with overprint in type I, correctly franked single franking on cover from "Ghyvelde 26.07.1940" to Dunkirk with reverse arrival postmark from "27.07.1940", faultless condition, expertise Lothar Herbst VP (2019: "the condition is perfect. The stamps are only in very small number of pieces known, therefore are they very rare. ", Michel 1.000.-