Thanks Shaun, I will look at both of those sites. Funny how the are both in Germany and no other places sell spares.
No Springman, I looked at the Imex web site and through their online spares catalogue and could not find any.
Hey Crius, looks like we are going to have an ongoing problem ! .... Might be worth getting an extra set as spares ?

Cheers Guys, thanks for the replies.
Steve