10 C. postal stamp and 90 C. "world exposition 1937 in Paris" with overprint in type I as correctly franked mixed franking on cover from "Ghyvelde 21. 7. 40" to Dunkerque with reverse arrival postmark from 22. 7. 40, in perfect condition condition, signed Pickenpack and certificate with photograph autumn VP (2014) : "the condition is perfect. The stamps are only in very small number of pieces recorded, so that they very rare are. ", Michel 1. 000.-