Lot 50 /Australia, Postage Due, 1907, ½d green, 2 complete right pane sheets of 60, one with watermark upright and "97076" machine serial number in top right corner selvage, other with watermark inverted, each with 'ST' of 'POSTAGE' joined flaw (position R9/1), all except one stamp never hinged, serial number pane with some crimped perfs at right, otherwise Very Fine, a exceptionally rare pair of sheets.
SG No. D45, D45w £1,680 for o.g. singles ($2,720).
Marginal markings on these issues are unusual and it is believed that they occur once in every 1,000 sheets and that the numbers were used for inventory purposes by the paper manufacturer.