Auction Series 257-264 in Zurich Day 4

Danube Steam Navigation Co 1878: 10 kr. green, Type II, perf. 9½, the unused sheet of 100 subjects of brilliant fresh colour, showing the characteristic double perfs. in four positions - the 78 mm. perforator was overlapped in the horizontal rows so as not to extend into the margins of the sheet; 'blind' perforations on the second, third, sixth and ninth horizontal rows (the only stamps in the world ever to be perforated in this fashion) with five perforations between the two blind perfs. Complete sheet margins at right and at base, the sheet with some inevitable creasing and splitting with protective hinges in places, large part og. with most unmounted og. An exceptional and extremely rare multiple for the connoisseur of these issues. Cert. Puschmann (1991) Mi = € 22'000+.rnNote: The issued stamp was almost entirely used in Bulgaria DDSG Offices until this new country joined the UPU in July 1879.
Catalogue 261: Stamp Issuing Steamship Companies