6 Pfg Heuss watermarked Z, horizontal pair with lower margin and printer sign "Fr" as well Part-HAN "1509. . . ", in perfect condition mint never hinged, superb in every respect (choice copy), the watermark-variety with printer sign is extremely rare and only isolates have become known, fine example, expertized Ebel and photo expertize A. Schlegel BPP "genuine, mint never hinged, perfect", by Michel unpriced