Just a quick update....
Before this cold weather hit I drained the cooling system down after disconnecting various hoses to make sure the whole system drained either side of the thermostat.
The parts have all arrived and as soon as Christmas is out of the way and the weather improves I'll be back at it.
I've decided to purchase the car and have been to the Post Office to get the log book application form, not sure if I can do that online but will look. I just grabbed a form whilst I was there

Corin has kindly offered to lend me his Bentley manual and a coolant system test kit that I will certainly take him up on
