Right everybody I've found the answer.
It turns out that orignial German MC's have small diameter plastic connector fittings and small rubber bungs.
After market ones have larger ones that are the same size as the ones used for the 944 MC.
These people have both:
Small
http://www.bughaus.com/master_cylind..._113611153.htm
and large
http://www.bughaus.com/master_cylind...113611153C.htm
And an image of the large connecting pipe, that I believe will fit the rubber bungs on the 944 mc once the reservoir is removed.
Cheers all
Jeremy