1, 50 Karbowanez with overprint "GK-Ssarny" in type I, position 7, properly franked single franking on cover with arrival postmark "Sarni -a 29 11 41", cover multiple folded - the stamp has in the right part of a vertical crease, photo expertize Gerhard Krischke BPP "the letter is properly franked franked also used. Commercially used letters of this kind are very rare. "