It must also be said that the original bearing was looking rather tired and dry, I don't recall the cars being slated for their shift action when new so I would imagine most are quite tired by now.
Therefore it was well worthwhile changing this rather than just cutting down the old shaft - which is far limited on how much it could be cut down by compared to the new one.
Unfortunately I cannot update my original post, but if anyone wants a short shifter kit for the Series 1 Aero - I whole heartedly recommend it, and for the first time in ten years you now can!