Cheers everyone!
About the offside driveshaft leaking seal: Because this is right side of the car I have a theory that the bearing behind it is worn and kind of wobbles in place which kills the seal. I have no data to prove it though! Is there any 'best practice' wisdom that the bearing needs to be replaced as well? Or perhaps I am just 'thinking too much'?
And thanks for your reply Guy! I'll keep in touch.