Bidding at $1,050 on this fake with this misleading description:
J21 (D43) 1903 10' dull green Postage Due, wmkd Crown and NSW, perf 11, very rare and substantially undercatalogued, perfectly centered, lightly canceled, XF
I won't claim to be an expert but I have accumulated significant knowledge of these issues in nearly 40 years of collecting them. The arrogance of an auction house ignoring properly referenced and accurate advice when they have made a mistake astounds me.

Tis is what a genuine one would look like (only 2 known like this, image from Prestige Auctions:
http://www.prestigephilately.com/ca...tionnum=115)