1917 Greece Serbia French Forces Airmail Cover
Greece: 1917 (4 November). French military with its contents cover exempt from postage to Paris struck by Tresor et Postes 502 for Salonica and Armee Serbes Aeronautique * Le Commandant *violet handcachet. It seems that the Serbian Air Force was still serviced and supported by the French. Signed and confirmed by sender diagonally on lower left with manuscript. Ex. W. Robertson.