"ΑΘΗΝΑΙ*1.ΜΑΙ.31" first flight cover to (MEDAN*8.5.31) (only trace of arr. canc.) by KLM with air-cachet 15aA in black, forwarded to "CALCUTTA*22.MAY.31", commemorative KLM canc. "GRECE-INDES" in red. Only 19 covers flown. (Hellas FF151G).