Ok, have finally got the opertating temp sorted on my Daughter's Corsa B 1.0 12v.
Turned out to be the thermostat - it's fine now with the new one and sits @ 92c which is spot on. You can see it open up/close etc on the warm-up and also the fan comes on when it gets hot. Sorted

I also flushed the system and blanked off the EGR and filled the system with nice new Vx red coolant mixture.
My (long winded) question is whether sorting the temp out and blanking the EGR will improve the MPG. She does 10 miles to work and then home again. Only done 280 miles so far in the car but it got through most of a (45L) tank of fuel.

I'm hoping that this will improve it significantly. The temp gauge previously never got off the end stop unless in heavy traffic when it would get to 92. The heater now get HOT, whereas before it was only warmish.
The car also had a full service just after we bought it, all except for the coolant/stat/EGR change which I did myself. The coolant flows through the EGR valve plate so it was necessary to drain the system to do that.
Comments please, thanks guys ........