10 C. Postage stamps issue \"Merkur head\" and 90 C. Charity issue \"Honore de Balzac\" with hand stamp overprint in type I, properly franked mixed franking on first days letter from Dunkirk 1.07.1940 to Ghyvelde with on the back arrival stamp from 2.07.1940, in perfect 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.-