BISMARCKHÜTTE, 5 Mark red-orange Steelworks and Dove of Peace 1920 as single franking on registered letter to Wilhelmshaven, double-circle BISMARCKHÜTTE 12 4 22 * (OBERSCHL) b (OS handbook No. 022.3), arrival (13.4.1922) on reverse, rare franking and interesting early inflation-period document, age and use marks typical of period