If anyone is interested, here's how I did it.
Apologies for the picture quality but my camera did NOT want to focus on anything...
First pic shows the edge of the chassis where I have had to file away a slight bit of the tub to get the corner of the GTB (where the sensor wire connects up) in.
Second pic shows - quite badly - where I have cut down the side of the chassis to fit the bit of power wire side of the speedo in. I don't know if this is the *right* thing to do, but it was the only it would fit.
It's a tight fit, but it's worth it... it's fast.
Gratuitous shot of the car...
