30 C. And 70 C. Postal stamps \"Merkur head with overprint in type I, properly franked mixed franking on letter from \"Ghyvelde 11.07.1940\" to Bray Dunes with reverse arrival postmark from \"12.07.1940\", faultless preservation, about the franking left little gum spots, expertise Lothar Herbst VP (2018) : \"the other preservation is perfect. The stamps are only in very small number of pieces known, therefore are they very rare. The stamp Bray Dunes is extremely rare, he is so far only as arrival postmark on covers known. \", Michel 800.-