Not a WW II bike, but still could have been ex-military.
We ran M20-21's down here till 1966 and a lot of them were tele forked.
We also painted the complete engines although the excort vehicles painted them with heat resistant silver frost and field units like signals & engineers painted the entire engine drab. with a broom by the looks of some I have seen at auctions.
Yes, post war BSA were very active selling to foreign governments, to companies for fleet use etc. etc....So, it could indeed have been a military machine...Ideal if you want to do Burmese Army re enactment or similar...
The Dutch, Thailand, Indonesia and no doubt others as well as Australia and Burma used them...Ian