Looks like car now sorted but, this post can be useful for anyone wanting a clean cooling system following CHG damage and coolant-oil mix.
The clean up seems to take longer than the repair.
Cheers Gnu,will get affected parts steamed off tomorrow and run a flush when re assembled to get any "nasties" out of the cooling system.
I have highlighted this as that is very important. It does take much time but, needs to be done to ensure a good repair. Far too many whip off the cylinder head and bung on a new gasket. There's more to it than that to ensure the job is done well.
best method i found is to pop a dishwasher tablet in the coolant bottle, hell i even stuck a calgon limescale one in there too lol run it about for 100 miles ish with just water and dishwasher tablet, then drop the coolant and all should come out!
I use a similar technique with SPEEDFlush. :~
I do not follow the instructions "on the tin". That recommends running engine at fast idle for a period then drain and flush. I prefer to put it in the cooling system with water, not Anti-freeze ( I usually do this in warmer months ) and run the car for a few days say 30-50 miles. Then drain and use a garden hose to flush out any remnants lurking in the cooling system. It is effective stuff. Then add 50-50 OAT Coolant and water to the cleaned out system. The muck that process can clear out is surprising.
So that this:~
and these :~
Look at what was lurking in that radiator.
I was told that radiator was so badly blocked it could not be recovered. It was.
Then the garden hose treatment ~ only water should now be in the clean system :~
Can become this :~
and this :~
Yes, thoroughness like that takes time but, pays dividends in making a car so much a nicer place to be and far less prone to have further problems. Plus, you can check the all important coolant level with a speedy glance as soon as you lift the bonnet.