50 cent postal stamp blue, vertical pair with overprint in type I, properly franked 1 Fr. Franking on cover from \"St. Pole. Sur Mer 22.7.40\" to Dunkerque with reverse arrival postmark 23.7.40, faultless condition, issued only approximate 3.000 pairs, photo expertize Lothar Herbst VP (2016) : \"the condition is perfect. \", Michel 600.-