6 Pf. black blue green, vertical strip of seven, once showing a double print, in perfect condition mint never hinged, unsigned, certificate Dr. Jasch BPP (2017) "they point at 3 x the plate flaw VIII on (F. 11, 41 and 71). . . Genuine and immaculate. . . And on all sides good outside borders. A crease of the lower stamp touched the double impression not. Double impression of this kind are rare. " Michel 4.050,-