Hi Dave,
At the risk of sounding simplistic, take the old one off and go in to your nearest motor factor or Ford garage and ask for a new one.  I realise it sounds a bit numpty but if you don't have much engineering experience it saves a lot of mistakes when the guy selling you the bit can see exactly what you want.  Any repair to a cooling pipe is just a bodge to get you home usually.
Cheers now
                
 Ken Chapman
                
 April 2007