1929 (November 2), Zurich-Dubendorf Flight mixed franking cover to Basel, franked by 10rp yellow green in block of four and Prince Johann 35rp brown and black, uprated by three Swiss air post adhesives, Friedrichshafen ''2.Nov.29'' connection and Zurich the same day drop ds, VF and scarce cover, Est. $350-$400 (Image)

1931 (June 10), Vaduz-Lausanne Flight Swiss stationery postcard 5c green uprated by Liechtenstein Zeppelin stamp of 1fr olive black, Lausanne ''10.VI.31'' cancellation, Vaduz red Flight marking and same day arrival ds, VF, Sieger #110 var, Est. $150-$200 (Image)

1932 (June 28), Switzerland Flight (250th Zeppelin Flight) postcard, franked by four air post values, tied by blue special marking, the same day Friedrichshafen connection and Vaduz arrival of June 28, VF and scarce, Sieger #166, €350, Est. $200-$250 (Image)

1933 (July 18), Switzerland Flight postcard to Luzerne, franked by Airplane over Rhine valley 1fr lake, cancelled by Triesenberg ''15.VII.33'' ds, green Flight marking, Bern drop and Luzerne ''18.VII.33'' receiver, mostly VF, Sieger #222, Est. $100-$150 (Image)