Three maps of New Britain. The earliest map, dated 1927, shows New Britain in relation to surrounding islands and the New Guinea mainland. It includes an index of properties and places, and shows plantations and trading stations. The other two maps were issued by the U.S. Army in 1943 and show sections of New Britain. An accompanying note by Anne McCosker states the maps were used by Stan McCosker during the war years.

Scrapbook of articles by Stan McCosker as printed in The Bulletin. The articles contain descriptions and accounts of life in New Britain. At the back of the scrapbook there are four loose newspaper cuttings from the 1960s and a typed article, 'The Epistle of Father Jerome to the Kiaps'.

Handwritten diary with daily entries relating to activity at Stan McCosker's gold mine, 50 miles (80km) south of Rabaul. Sections towards the back of the journal contain lists of labourers and what appear to be accounts of payments made to them. There are also lists of tools and supplies. The journal encloses an unattached letter from 'Pop' to 'Bin', dated 31 December 1955 and 3 January 1956.

Correspondence, a statement of claim and associated documents and a copy of a judgement in the Supreme Court of the Territory of Papua New Guinea in the case of Stanley McCosker and Henry Walford King (plaintiffs) and Gustav Thomas Kuster (defendant). The Court ruled in favour of the plaintiffs and an application by the defendant Kuster for leave to appeal to the High Court of Australia was refused.

Two ledgers detailing expenses, incomes and assets of the Matala Plantation from July 1954 to June 1955.

Correspondence, statements and asset inventories relating to a claim to the War Damages Commission for war damage to the Matala Plantation during the Japanese military occupation of New Guinea.

Two letters and typed manuscripts of 10 short articles about life in New Britain.

Newspaper cuttings of articles about the German plantation owner and trader Heinrich Rudolph Wahlen and the house he built on Maron Island in the Hermit Group of islands of New Guinea. The file includes a photographic print of the house.

Assorted newspaper cuttings and articles about Heinrich Wahlen and other topics relating to colonial life in New Guinea. The file also contains letters from Stan McCosker to The Bulletin.

Assorted notes, newspaper cuttings and other documents relating to the publication and launch of Masked Eden.