Sorry but the chain rubbing on the front mech or anything else is something I learned how to fix a long long time ago LOL!
It is now back to silent running after the 'service' I gave it, so I suspect Jenkins you were right. Although I don't have a torque wrench I tightened that bad boy up quite strongly. I'm sure the clean and relube etc contributed a tad but that extra crack on the chain ring lock nut is what did it IMHO. Thank you all for your inputs, much appreciated.