United States. Small Collection: 1925-36, Five Zeppelin covers, including Bermuda Return Flight (1925), Around the World Flight (1929), Chicago (Century of Progress) Flight of 1933 and two covers of the First NAF by ''Hindenburg'' of two different types of receiving postmark, minor flaws, still F/VF, Sieger #20P, 28D, 243D, 409B, C, €430, Est. $140- $180 (Image)