PureH2O has answered it all for me
You saw off the end of the current gooseneck.
File off the outer surface until it tightly fits the plastic end converter.
Slide this on and mark the centre of the hole.
Remove and drill a 10mm hole on this mark in the carbon neck.
Clean both surfaces apply glue to both and fit.
Ensure that it is correctly aligned whilst drying.
Using PU hose slide this through the hole and down the gooseneck.
Job done.