Here are some First Day Covers from Sarawak:

06 November 1945: Australian Stamps for Use in Sarawak

These 4 Australian stamps were supposed to be released for use on 06 November 1945. Thus far, I have only been able to locate philatelic covers cancelled on 08 November 1945. If anyone has the first day of issue cover, can you send me a photo of the image for use in this website?

17 December 1945: BMA Overprint Definitive

The FDC below is cancelled in Brunei.

18 May 1946: Sarawak Centenary

16 April 1947: Sir Charles Vyner Brooke (cypher overprint) Definitive

10 October 1949: 75th Anniversary of Universal Postal Union

03 January 1950: H. M. King George VI Definitive

01 February 1952: H. M. King George VI Definitive

03 June 1953: Coronation of H. M. Queen Elizabeth II

01 June 1955: Queen Elizabeth II Definitive

01 October 1957: Queen Elizabeth II Definitive