BORSIGWERK 14.4.1921 ZKr (032.2) on cover with multiple franking 30 Pfg yellow orange horizontal pair postage stamps issue smelting works and peace pigeon to Zawodzie, stamps with perfin (perfin) "A. B. " about 90 ? left turned (A. B. = August Borsig Borsigwerke AG Mining and Smelting Management, Borsigwerk / Upper Silesia, OS handbook number 1), transport traces