[Ameiseuk]

As with most manufacturers the common bits are mass produced by outside contractors. Audi arent going to have just a couple of thousand ball/socket combos produced just for a d2.
If the linkages are ok, the engineer in me would try and source the linkage off another vag group car of similar 'size' ... vw phaeton, wv passat or audi a6 spring to mind.
There are bound to be nos ones floating about on ebay or similar.
Use the ball/socket off these and repair your own. The bits are normally clipped in or worst case a circlip to hold them under the gunk.