I spent a lot of time on this aspect of the build, so I hope it is worth it. It was not as perfect as I had hoped due to about 1mm of edge.
Basically I have remade the mounting brackets for the Andair Fuel Valve and it's extension. In the process wanting to raise the valve knob so that the tunnel cover fit snug over it and was fully supported.
This was achieved, however there was absolutely NO free play in the edge distance, therefore the tunnel cover must be 'placed' into position firmly.
The Fuel rotor and mounting plate now are set snugly into the tunnel cover. This will allow me to take off the tunnel cover and not disassemble the Fuel mounting plate in any way.