Hi Squire, looks like the gasket on the rocker cover is shot, common on vauxhalls as I mentioned, to be honest with you its a garage job and it,ll work out at about £200!! In the meanwhile take the plugs out and clean all the oil out of the plug holes and clean the plugs or by some new ones, this will keep you going for a while but the problem will return, wish I could help more, best of luck
popeye1948
June 2009