Katowice 19.8.1921 ZKr (141.25) on cover with 10 Pfg orange red part sheet to 10 stamps with vertical gutter and right margin, latter with punchings, numeral "2" and marker cross on margin to facilitate cutting or perforating of panes (field 31-32, 41-42, 51-52-53, 61-62, 63) postage stamps issue smelting works and peace pigeon 1920 to Steinbillen / Switzerland, transit postmark ZKr AARBURG 21.3.1921 at back, very unusual unit and multiple franking, transport traces