The car has now gone back to the dealer we bought it from and they are fitting a new turbo at this moment. They started it the day before yesterday and the guy said I would get it back the next day but I think he's dreaming! We're now on the third day and I know from experience that a turbo job can be a nightmare on some vehicles where most of it is hidden down the rear of the engine.
When it returns I''m thinking of performing some major servicing that dealers don't tend to do. Namely, drop the sump to change the oil pickup and to have a look at the cams to see what condition they are in., plus new injector seals on the re-fit.
Hopefully, provided its not ever had the "low oil pressure" saga, it'll be fine.