Hi Steve,
I've had the air strut/ shock absorber replaced today with a second-hand part I bought from Nippon Auto Spares In Derby for £129.
The part is in very good condition and has transformed the driving experience. Turns out that the old strut had a worn bush at the bottom that allowed vertical movement of about 2cm, so was very skittish on uneven road surfaces and when pushed on that corner.
I've got the old strut in a box in the boot of the car, so just let me know when you'd like it to be picked up.
Regards,
Adrian