Well if it was smoking on boost as well I figure that would be the rings gone but its smoking big time only on overrun and a little after its warmed up.

I checked the hoses earlier for any oil in them but they were dry.

Think I agree with the oil change and while am at it gonna change the stem seals as I got that nifty tool for doing it with the head on. They are only a few quid but gonna try and get genuine Ford if possible. Halfrauds have got some sh1tty 15W40 mineral oil for £15 so why not.