Afraid the quote is all I have on this one, it was just an email from ages ago.
I had a browse in my library. Unfortunatley the larger of the books I have on the
exhibition is a politically biased one, and indexes people rather than building or features. The other is smaller and skip through it only showed the South African Pavilion, near to the Canadian Pavilion.
Going by what I can make out, it is rather small and ornate, so not much reason for it to go to Ardeer.
I suspected Africa House was something bigger and potentially more useful, but having said that, I also have a map of the site (missing 8 buildings though) and it only lists "Union of South Africa" in the right place, one building distant from Canada.
There's another colour photoset
here.