My ds9 has an exceptional wm - but doesn't have some of the traits you have described now. He seems to comprehend everything, it seems. He has the perfectionism and anxiety on/off though. Also has the high math ability. We've been trying to encourage him to play the piano but so far no luck.
IQ testing is somewhat different than what Barry Scott Kaufman's article addresses and other research have done. Daniel Tammet is from the UK and you may have better luck with who has studied him than your average tester. I'd try to find an academic who studies kids with exceptional wm if I were you.
Dh is from the UK, but we're in the US now. We've been thinking on/off how glad we're not in the UK at the moment with this - but also how we may at some point move back for educational opportunities. We'll see.
