So, returned from a Europe trip last week covering 1350 miles and it's been faultless! I bought the car on 82k miles and it's now sitting at a pretty 96k.
Only needed a basic service (oil, oil filter and air filter = £34 using Eurocarparts 56% off) and re-fueling.
After tweaking the ECU more over time, I get a genuine (tank to tank measured) 60mpg at 70mph.