Update :
I found a complete wheel bearing / hub from a breaker on ebay. Only 25 quid delivered and now installed , car is back on the road
There only seems to be two types of hub, at least on the lower models - quattro and non-quattro. The hub I bought was from a cabriolet but was the same part number as a saloon, it appears the estate models are the same too. (8E0 505432AF)