Postage due stamps world record letter, fourfold sent on and fourfold with postage due stamps franked cover. With 12 Pfg Hindenburg (corner fault) from "Brunswick 29. 11. 36" to Innsbruck-Mühlau / Austria, thence in the Czechoslovakia forwarded and there further three times forwarded. The cover was in Liberec, Komotau, Ground stream and in Prague with postage due stamps franked. An extraordinary document! (former starting price 400)