Eddles, phone Superchips and ask them. They will either recommend a Bluefin, or a trip to their rolling road.... or there's a tuner up your way that does specialist one off maps for customers. I think its RS Tuning in Leeds
Cost is normally £450 IIRC, but if you are a member of
www.tdocuk.com (free membership) it will cost £395 with before and after dyno runs and graphs.
What can be done is the injection advanced and the rail pressure increased. This will give very good FE benefits, but emissions will go out of the 'regulation' limits. This is nothing to worry about tho as its something the manufacturer has to do when the car is produced. Won't affect MOT
I used to be a Diesel engine calibration engineer for Ford, so have a bit of knowledge on this subject.