Hi All. Problem sorted. I followed the advice of westcott and looked for Ford Granada parts. I started searching for spares in UK, but couldn't find anything. Eventually, I saw something that looked like it matched, which lead me on to lots of US sites where they stocked the part I was looking for. Fortunately one of the guys I work with was out in the states this month and I ordered from the nearest "O'Riellys" store and he went an collected it for me $5.29 !! Result. A bit of drilling out rivets to get inside the fan box, and it fits perfectly. For future reference it was a Murray Blower Motor Wheel p/n 35528. Many thanks to everyone who helped. Much appreciated!