1902-04 Base Completed Watermark Crown over NSW 1/- and 2/- used on 1905 (12 May) Tattersalls cover from Cathcart (Cape Colony) to Hobart with 1d, underpaid 1½d with handstruck octagonal 'T/15', the 1/- and 2/- postage dues affixed and tied by Hobart cds. The correct charge should have been a double deficiency of 3d, and this is clearly a case of the shilling values being accidentally used instead of the pence values. The only such instance of which we are aware, and a clear demonstration of the need to differentiate the shilling values by the addition of a stroke, which did not happen until 1908-9. Very fine apart from the usual repaired spike hole, and the only recorded example of the 2/- postage due on cover (BW cat AU$1500)