Australia New South Wales 1890-91 20s cobalt-blue Official, SGO50Australia New South Wales 1890 91 20s cobalt blue Official, watermark 54 ("20 "), right marginal with part "(O)NE POU(ND)" imprint, cancelled to order with large part concentric oval, SGO50. A fine used example leaving profile almost entirely clear. A few slightly shortish perforations as often seen, but a really fine for this rare Official stamp. New South Wales celebrated its 100th anniversary in 1888 with an issue of what is widely considered to be