Thanks for all the hello's people
Welcome to OOF. As said,you sound pretty able. 
Most folk here would agree though that binning the plastic cam covers isnt the way forward.Crank seal may be the next thing to go now. 
Albs, Yeah I've heard people say that, the change was partly due the cost of new plastic ones being silly and didn't want to risk another set of plastic ones that were second hand and fatigued. We'd already tried getting the plastic ones to seal a couple of times (after thouroughly clearing the breathers), they looked a bit tired though but I imagined most second hand ones to be the same. Just couldn't afford to spend any more time trying with them. Each time they lasted about 500 miles before seeping again. I take it V6 vectras have a different breather system/are not prone to blocking?
Sorry I'll go find the right area to discuss this when I get a moment.
Right better go lay underneath it and get all depressed once more.
Thanks for the replies