I'll try Graham!
I have another thread running on this topic on a hillclimb thread with a few contributors helping me.
I decided to lash-up one of the sugestions.
This simple appraoch is based on the ELVA 200 formula car design that used a VW box.
Here the linkage is fixed to the gearbox shaft very close and direct as possible to the box.
It works, but the width of the neutral slot in the H is very tight, about 10mm at the lever knob.
Thus it will be very easy to select 1st going from 2nd to 3rd...
This equals a buzzzzzed engine and a 4K bill.
I think i have a final solution to this problem:
A full Porsche Boxster drive train with an auto/tiptronic box!