These came with a lot I bought. Two are King of the Plains (showing the back of one) one King of the Air. The other two were Australian (one Prince of Wales visit to Oz in 1920, one 150th anniversary 1788-1938) so I assume these are also Australian made. I would think King of the Air would refer to Charles Lindbergh – see an example here
https://www.worthpoint.com/worthopedia/rare-1927-charles-lindbergh-pinback-king-of-the
Any guesses as to who King of the Plains might have been? Because of the similar printing I would assume it would date to the same time as the Lindbergh pin, late 1920s. An American cowboy rodeo star, movie star? Any help appreciated.
