Registered double weight cover fr. with 80l. carmine canc. "ΑΡΓΟΣΤΟΛΙΟΝ (ΚΕΦΑΛΛ.) (110)*5.ΜΑΡΤ.71", boxed "ΣΥΣΤΗΜΕΝΟΝ", arr. "ΖΑΚΥΝΘΟΣ*6.ΜΑΡΤ.71". Wax seals on reverse. Very fine and very rare inter-Ionian postal rate cover. (Hellas 22b).