Portugal. (Poland - Great Britain - Postage Dues). 1924. Envelope addressed to 'The British Legation, Warsaw' bearing Great Britain SG 400, 1 1/2d brown tied by London date stamp '18th Oct 24', underpaid with boxed 'T/ 35' (London tax hand-stamp) and bearing Poland 'Warsaw Local Post' Yvert 52, 20,000 black - blue (pair) tied by Warsaw receiver on face ''20th Oct 24' and hand-stamped 'Unieta' in purple and forwarded to Portugal with Portugal postage dues SG D580, 8c green (2) applied and tied on reverse by Lisboa arrival and re-directed to the British Legation, China'