Hi Ozzy
Yes! Great book isn't it? I have a copy which my wife tries to use as a doorstop.......

I know what it says in the book. But my question did not include the word 'order' ;)
OK, I will come clean..........
The answer is ESTONIA ;D

My source was 'Supermarine Aircraft since 1914' by C F Andrews and E B Morgan published by Putnams. (page 244). Interestingly, the same E B Morgan at least confirms that Estonia did send a delegation in July 1938 in the book that you are referring to (page 76).
Anyway, thanks for having a go at my questions.
Cheers Paul