EL from "ΑΡΓΟΣΤΟΛΙΟΝ (ΚΕΦΑΛΛ.)*3 ΙΑΝ. 69" to Taganrog with manuscript "Via Vienna" fr. with 80l carmine and 20l steel-blue with VAR. "Inverted 0" (pos.79),(Hellas 35dNb+29b) and boxed "PD", via "ΚΕΡΚΥΡΑ (106)*4 ΙΑΝ. 73", "VOLOCHISK" and "WiEN*19/1", arr. "TAGANROG". The 100l. rate was for prepaid letters to Russia via Austria according to the 1867 postal treaty between Austria and Greece. Unsual route for this destination as the usual was through Constantinople. EXTREMELY RARE ERROR ON COVER.