2 silver penny black on blue, diagonal bisects (left half) on cover from \"14\" Gandersheim 2.4\" to Wolfenbuettel, expertized Thier, Georg Buehler, photo certificates Walter Engel (1981) \"genuine and immaculate\" as well Georg Buehler (1980) \"genuine and in fine condition. Great rarity\", Michel 12.000.- - provenance: collection Gaston Nehrlich.