Hi Mark,
I have thought about this conversion many times myself. What i figured out was you would have to relocate the hole for the vertical pivot rod as close to the shifter as possabile so as to hide it under the leather boot of the shifter, this would require shortening the upper rods from the shifter and adjusting the underside rods to the required length .
OR
You may be able to make a kind of Z shaped rod go straight from the shifter through a hole linked to the gearbox selector. I will have to have a better look at my brothers car and shifter to see if such a conversion will acctually work.
Kenny.