1915 (4 May) U.S. 2c envelope used from Pittsburgh to Sydney, circular 'CENTIMES/30/T' applied, censored on arrival, and with 1909-10 Watermark Crown over Double-lined A Thick Paper 3d affixed and tied by Sydney cds. A very scarce value on cover, and undercatalogued by BW at AU$200

1916-20 6d Blue Kangaroo envelope (230 x 182mm, with internal linen pouch) inscribed 'Wool Sample only' and with printed address for Messrs Krelinger & Fernau, London. Archival records indicate that 1,641 envelopes were printed in November 1916; no used examples are recorded. Fine mint and very rare, with only five complete envelopes recorded. A major Australian Commonwealth postal stationery rarity, BW ES10, cat AU$6000