BRUNEI - JAPANESE OCCUPATION: 1942-44 Handstamped 'Imperial Japanese Government' 2c orange & 15c ultramarine SG J3 & J13 tied by Japanese-style Brunei Town Central '10/1/2605' d/s to locally-addressed envelope endorsed "First Day Cover 10.1.1945 (2605)", a couple of very minor blemishes. Gibbons provides only a year of issue for J3 (1943) & J15 (1944); this local source suggests they were issued later.
BRUNEI: 1945 (Dec 17) endorsed "FIRST DAY of ISSUE - BRUNEI..." with Sarawak Charles Vyner Brooke 'BMA' Overprints complete set to $10 tied by multiple fine to very fine strikes of 'BRUNEI/17/DEC. 1945' Linotype d/s, a couple of minor bends & blemishes, Cat £750+, for single stamps used in Sarawak. Gibbons states that the stamps of Sarawak & North Borneo were available for use in Brunei until the reappearance of Brunei issues on 2.1.1947, but does not list or price their usage in Brunei.