Auction 333-341 Australian States & Commonwealth of Australia and New Zealand – The ‚KOOYONG‘ Collection - Day 2

1900/05: Postage Due ½ d. scarlet & pale yellow-green, wmk. Crown over A variety Inverted, variety "compound perf. 12 x 12½ and 11", an unused corner marginal horizontal pair from top right of sheet, showing additional vertical line of perforations perf. 11 and both gauges in the right hand margin - perf. 11 being on the inside and the 'extra' line of vertical perfs. being 12½, of excellent fresh colour, superb unmounted og. Cert. RPSV (2024) Brusden White VD39 = $ 2'500/Gi = £ 1'600*.
*Note: The Stanley Gibbons listing is for a compound perf. error, however the Brusden White catalogue is more accurate stating "mixed perfs.", the BW catalogue states that this error was first recorded in 1913 "These are from the right coloumn of the sheet on which the final strike of the comb was omitted, corrected initially by a poorly placed line perf. 12.4 strike, then correctly positioned line perf. 11 inside this. At least two sheets were treated, since examples with both upright and inverted watermarks exist. Four unused examples with watermark upright are recorded." The above pair appears to be the sole example so far recorded with Inverted Watermark.