Thanks very much mick01.

That's a huge relief to hear. It's been over a month and about 1,000miles since the replacement. So far there's not coolant leak or fault in the heater and temperature; the gauge goes up steadily to 90c after 10min drive or so and stays there as it should. I'd like to think that the repair was successful for now!

Thanks very much everone once again; without this forum I wouldn't have done it myself!

So it's just the turbo that needs looking after...