Germany, Third Reich. A Mixed Lot of Zeppelin Airmail Envelopes and Cards

(Zeppelin Luftpost). A mixed lot of Zeppelin airmail correspondence, consisting of three envelopes posted to recipients in the Netherlands, Switzerland, and the United States, featuring appropriate stamps and stamped marks, the latter unopened and retaining a letter, accompanied by an additional card addressed to Recife, Pernambuco, Brazil, an interesting a researchable group in extremely fine condition.