Hi,
I think this is the car from Sedgefield, which I inspected and had a test drive in.
Have a look on the Barchetta owners technical pages for the wheel bearing replacement it mentions that there are two types of wheel bearing, one of which is for ABS
The brakes had just been fixed by a garage, could you not take the car back to get the fault rectified?
You've mentioned a rusted through floor, when I had a look over the car, it had been standing in the rain all day, and there was 2 inches of water sloshing around in the torneau locker which suggests the seals on the torneau locker need replacing and/or the hood isn't waterproof.
It maybe worth a look at the DVLA site which lists all the MOT's from 2006, so you can see what issues the car has had, one of which was a rusted seat belt mount!
Hope this helps. If it is the same car, then I think you got a cracking motor for the price