Airmail, 1933 Chicago Exposition Flight. Friedrichshafen to Sevilla, cover franked with 1933 50¢ Zeppelin block of 4 (perf wear at top) tied by New York machine postmark, violet U.S. and red German flight cachets; light cover toning, Fine. Sieger No. 241F. Scott No. C18  Estimate $100 - 150. $0 (Image)