By the year 1949, Brunei had issued only a handful of stamp designs - the 1895 Brunei Local, the 1906 Labuan Overprints, 1907 to 1947 Brunei River Scene and additional Kampong Ayer scenes. In October 1949, Universal Postal Union was celebrating its 75th Anniversary and all countries around the world issued their own stamps to commemorate it.
Around 70 countries and territories of the Commonwealth issued a set of identical stamps. The designs were the same for all 70+ territories with the exception of the colours, the postal amount and the name of the territory. Brunei issued its own 4 stamps. Recently I managed to acquire the First Day Cover which had the 4 stamps addressed to someone in Sandakan and was postmarked 4 November 1949 from Kuala Belait.