25 C. Merkur blue-green as block of four with two vertical overprinted note stamps pairs as properly franked 1 Fr. Franking on cover from \"Dunkerque 2.8.40\" to Malo les Bains with arrival stamp from 3.8.40, faultless condition, signed Dartyre as well photo expertize Lothar Herbst VP (2015) : \"the condition is perfect. The stamps are only in very small edition from 800 pairs issued become. There only a small proportion of it have been preserved is, are such stamps very rare. Different overprint position (K) \"falling) top down running) is as special feature to mention. \", Michel 2.100.-