Attempted to fix it yesterday with some metal bonding putty, I figured that as it was Good Friday, and there wouldn't be any dealers open, I may as well give it ago. The putty worked well, bonded the two corner bolt holes on well, I recommend it for any metal bonding job that doesn't require too much strain on the part(£3.49 from Halfords), for a seal like this that only needs to be nipped up, it was fine. Anyway, I fitted the repaired seal cover, re-attached the drive shaft etc, sat back proud of my work, then realised the seal gasket was still sat on the workbench, id forgot to put it back on before fitting the cover!
After a lot of cursing I set about dismantling to get the seal cover off the drive shaft AGAIN, fit the rubber seal gasket, put it all together again, topped up the oil, only to find it leaking again, but this time not from the repaired bolt fixing, but the actual seal around the drive shaft! absolutely gutted!!
I took it off once again, and now I'm hoping to buy a new complete cover with the seals from the main dealer, it was worth a try I guess, and at least I know that when I do get the new unit, I'll be able to fit it within minutes with my eyes closed after my 4 practice runs
Cheers for all your responses guys!