An update,
I managed to track down a FSI rear axle that was advertised by a member (Zaphodbb) on eBay (thanks).
It was the one from Hilary's car, so now it will be a significant part on "the Project"!!
I have dropped it of at my mechanic, it was in good condition and so I will not be getting it blasted, just power washed and painted.
I now have every other part that goes onto the axle sitting in boxes all brand new (every part even down to brake pipe clips (even the little cross head countersunk screw on that retains the disc).
So when it is done it should last as long as the rest of the car. It seems that the rear axle has the most ferrous metal on the A2 and so with this sorted, the car should last longer than I will.
It won't be done in time for the meal (of course) but it will be good to get this final part of the project finally completed.
I now have the other axle to get rid of (all zinc plated and powder coated) If anyone thinks they could use it they can have it. It looks like it is one from another VAG car (Polo etc.) or it might just be as the seller has stated, the later A2 version that was fitted as a replacement part as late as 2008, who knows.
Steve B