Letter from Vienna 23.6.1866 underpaid with 15 Kreuzer instead of 30Kr because of the Convention between the Austrian Lloyd and Greece regarding the former Ionian Islands the missing amount noted with 15 (Kr) and taxed in Corfu with 65l. Rate 15x3=45+20 local = 65 lepta. Very fine and very rare impressive item. Certificate Guy de Vachat.