Great Britain 1920 Postage due cover from Australia, SGD6Great Britain 1920 Postage due, SGD6. Very fine cover from Australia endorsed "Via Mantua" bearing a d green & 1d deep red brown (SG20+59), cancelled by Katoomba N. S. W. circular date stamps for DE. 3. 1920. Addressed to Folkestone and deemed underpaid with a "4d I. S." handstamp, the charge collected by a 4d dull grey green postage due cancelled by a Folkestone circular date stamp for JA. 11. 1921. A scarce and interesting piece of postal history.