Suddenly remembered today that I should probably let my insurers know about the turbo, and then discovered that they won't cover me At this point the sensible thing to do is to forget the whole thing.
So I promptly cancelled that policy and took out another one! Lost about £200 due to cancelling a policy mid-term, but it's not too bad really. My own silly fault, didn't even think it would be an issue at all.
Am picking the car up tomorrow from one garage with hopefully functioning brakes, then dropping it off for the conversion on Saturday at another which should be done Monday, so I might have half a chance of having the car ready for Bedford next weekend. Hopefully...