It figures that there are a few South African examples still around, as there were several orders placed by the War Office: for 1,000,000 in January 1942, 250,000 in July 1942, and then 1,500,000 from September 1943. Perhaps much of the output went to India for the Burma campaign; Malaya and Singapore would have fallen before they could have been supplied from the first order for one million.
At the time of the first SA order, January 1942, there were also orders for 1,000,000 from New Zealand and 500,000 from Australia, which all might have been a reaction to the developing crisis in Malaya, Singapore and Burma at that time.
Tom.