Ahh,
THAT Whirlwind ! Hope you can understand my confusion, though I should have taken more notice of the cockpit photo's.
I think Eric 'Winkle' Brown test flew it, may be worth trying to contact him ?
A check of his book/s first would be an idea just in case it's mentioned, I'll have a scan through ' Wings On My Sleeve '.
The only person I knew who dealt with them is no longer with us, but being ( just ) effectively post-war, there must be a lot of people out there with the knowledge; maybe worth posting on the Military Aircrew forum too, with the explanatation someone's dad may have worked on / flew them ?