Hi Chris,
As you and Murray said, you have an early chassis there. The KVA moved on to the "C" type chassis which more closely replicated the original type.
As far as I understand, quite a few early chassis owners had their rear chassis changed, and I THINK, this became a speciality of GTD before they started building their own chassis (please someone correct me if I'm wrong here)
The (rather convoluted) reason why I am mentioning it, is that IF you did decide to update the rear end suspension to the GTD setup, I have a GTD rear chassis section sitting in my garden here doing nothing. You are more than welcome to it as it's only going to the dump otherwise!
Simon
simonjrwinter@hotmail.com
ps, looks like you've got a damn good start to a car there!
pps, so, do we now know the heritage of the GTS tuning car?