Thanks for All the responses so far, On the corrosion, It was only the edges of the combustion chambers , Not all of them only two, So welding up and skim, brought them back to perfection.
Job done at reputable engineering works, So I gather it was tested after weld, I'll inquire on Monday tho.
Thabetha> Never is this car going back to that idiot!

I can and should have done it myself in the first place, But thats spilled milk, I just have to sort it out.

I got another hint that , He removed the Stat, and did not replace it, CAn this have a effect of this nature, Or will it run only taking longer to heat up.

I will anyway install a new stat this afternoon, fingers crossed!

Thanks so far.