In 1929, Honduras released its first air mail semipostal stamps. The series consisted of four different overprints on an airmail stamp issued on the same day. The design commemorates the flight from New York to Honduras by pilot L. Garay, with a perforation of 12 and an initial value of 50 Honduran centavos. All stamps were printed using the recess printing method. To learn more about Honduran philately, watch this stamp chat. 

Original stamp below and overprinted stamps above

In 1945, a pair of stamps in 5pf and 8pf denominations depicting the Berlin Bear was issued by the Soviet administration in Germany. These were the first new stamps issued in conquered Germany at the end os the second World War, although the British and Americans had placed the Military Government stamp issue on sale on March 19 and there were also stamps featuiring local uses of obliterated Hitler heads. The Soviet occupation zone of Berlin is now part of East Germany. To see a detailed collection of the stamps of East Germany, including later issues, see this part of our refrence collection.  

Two stamps issued by the Soviet occupiers in what is now East Germany 

In 1961, Mongolia featured mail handling on its first air mail stamps. The set marked the 40th anniversary of the countrys independence and even featured a souvenir sheet. 

Examples of some of the first airmail stamps of Mongolia

In 1966, Great Britain introduced the Machin Head definitive design. It is widely considered as one of the most beautiful and recognizable definitive designs of all time, especially the intaglio printed high values. More information about the machin stamps can be found in this article and this library guide.

The Machins depicted in this example were issued on March 5, 1969, in the pre-decimalization era.