Thanks Andy for the information. Had to go for another product in the end due to time restraints.
Unipart sold me this stuff as they have all local garages come in and buy this all the time and they swear by it.
http://www.granvilleoil.com/product_info.php?prod_id=46
Changed the old plastic Oil Separator plate (for metal) and found several cracks around the screw holes on the old plastic one, but still changed the rear crank shaft seal again just in case. Just wished I had changed both from the start!! live and learn. Used the sealer on the new cover. Fingers crossed no more leaks now.
Thanks again AndySpecD