Mexico, 1936 North American "Hindenburg" Zeppelin Flight, registered flight cover franked with Airmail 1934-35, 5c black + 40c blue, pair + 1p gray green & red brown + Regular Issue 1935, 20c ultramarine, all tied by Mexico cds's, registry and "Via Airship Hindenburg" etiquettes, reverse with New York transit and "Frankfurt, 23.5.36" receiving postmark, Very Fine and scarce. Sieger No. 411D. Scott No. C65+C70+C72+715  Estimate $300 - 400. $0 (Image)