thanks for the advice, the hub that was fitted was genuine VW, so Im not too worried about that
however, having seen under there the small gap, Im wondering if the ring of the old hub had contacted the sensor, so I have ordered a new one
the wheel bearing made a slight rumble, so I drove it home the 2 miles, after all they rumble for ages in my experience, however, while exiting the roundabout half a mile from my house it made a bit more of a clonk, got home jacked the car up, grabbed the wheel top and bottom, preparing to give it a good tug, and the top of the alloy wheel had near on 1" total travel!!!
the garage that took it apart said the bearing was rusted up in a major way, internal parts of the bearing were missing, and the hub had been turning in the bearing instead of vice versa, hence the new hub being fitted.
with the amount of movement that it had, Im half expecting to see that the sensor has had the end shaved off LOL
couldnt afford a genuine sensor £62, so hoping that an aftermarket one will work ok, hopefully have it by the end of the week, and fit it on my lunchbreak.
thanks for the useful information and advice.