10 M. Posthorn, overprint type II, upper margin foursome souvenir sheet with the cylinder combinations 0'6'0 / 1'5'1 and 0'6'0 / 0'7'0, in perfect condition mint never hinged, unsigned, superb in every respect (choice copy), in this combination extraordinarily rare, photo expertize Weinbuch BPP (2018) "genuine, perfect"