
Yay, the pic worked!
I've managed to get the pump off without breaking anything else and can give you all some more details.
The pulley is approx 110mm diameter. The pump is stamped (nearest the pulley) with J3X, and the end of the pump (furthest from the pulley) is stamped 092735 or it could be 755, it's not very clear.
As you may be able to tell from the pic, it has 6 "plugs" around it, 5 would be undone using Torx sockets, the 6th is a bolt (these are visible in the pic). It was difficult to tell what was wrong with it apart from there is a leak somewhere, and even with it off the car I still can't tell!
I think my best bet is to replace the pump and perhaps send the old one off for recycling.
To finish then, if anyone has the correct replacement pump, let me know and more importantly, how much