First Australian WO orders
 

"By the late spring of 1941 all parties in London including the Bank of England had agreed that there was an obligation to keep Canadian production running as much as possible. This was assisted by the [British]War Office. receiving approaches from the Australian Government at that time for 10,000 Canadian vehicles, for Australian service in Australia. These differed from Indian and Middle East orders because the Treasury had no control over Australian orders. Nevertheless the attitude became that if the Australians did not have sufficient Canadian dollars then Britain would lend them": Various Memoranda, May to July 1941, File T1096/105, National Archives,London

I just found this in my papers. This possibly partially explains why the Australian Government purchased ex-British vehicles delivered to the Mid-East. We know that these were purchased through London. The same applied to the NZ Government although I have no information yet on the Indian Government because the W.O. supplied the Indian Army direct pre-war.

However as to the first series Canadian orders placed by the British for Australia under the above agreeement, my information says:

changed because 145 units were noted in Canadian archives to have been delivered to Australia and if they got there, 150 for Singapore although they could have been diverted.

The earliest known dedicated Chevrolet S/M demand was S/M 2126 and 2127 for C60S/F60S on a mixed basis, CKD for Australian assembly.