I was originally going to send the Buddy Club coil over away to be repaired, but there was nobody in the UK who could do this, which means that I would have had to send it back to Japan. I thought about buying a new replacement strut, but the costs meant it would be more cost effective to buy new suspension all round.
After a lot of research, I decided on the Tein "Winding Master" Monoflex coil overs which arrived the other day and me and my brother-in-law fitted them at the weekend.
As it turns out, one of the front struts was leaking oil and about to go so it was a good job I bought the new set. The car feels much more stable with four working struts. We set them up as close to the old Buddy Club coil overs as we could and I will get Abbey Motorsport to fine tune and corner balance them next time I'm down for a service (which is due soon).