Air Post stamps. 1924, Monoplane in Flight, 5m-45m, imperforated complete set of triangle stamps in blocks of three, arranged on a piece and cancelled by large red circular United Postal Union marking ''Postes et Telegraphes. Madagascar. Collection de Berne'', these specimens were provided by UPU to postal administrations for information about issued stamps, fresh, VF and rare item, Est. $200-$250 (Image)