Cover (envelope) mailed registered, linear "ΣΥΣΤΗΜΕΝΟΝ", fr. with 2x20l indigo blue and 10l red-orange, canc. "ΛΕΩΝΙΔΙΟΝ*5.ΜΑΙΟΣ.79", via "ΑΘΗΝΑΙ*7.ΜΑΙΟΣ.79" and "ΠΕΙΡΑΙΕΥΣ*7.ΜΑΙΟΣ.79", arr. "ΚΩΝΣΤΑΝΤΙΝ (ΤΟΥΡΚΙΑ)*11.ΜΑΙΟΣ.79". 30 lepta the UPU rate and 20l for the registration. A small part of flap miscut and wax-seals removed, still very fine and attractive. (Hellas 51d+50c).