KATTOWITZ, 10 Pfg orange-red (reverse), 15 Pfg grey-violet, 20 Pfg blue Steelworks and Dove of Peace 1920 on black-and-white picture postcard to Konstantinopel (Istanbul) / Turkey, double-circle KATTOWITZ 10 11 20 * (OBERSCHL) g (OS handbook No. 141.29), unusual rare destination, age and use marks typical of period