I wish I weren't so impatient! Had no Internet all day and decided to go to a garage near work.

It is a single unit and it's now on order @ �40 for one mount! Because I'm going on a bike safe course with the police on Sunday I said yes to the part and 30 mins labour. Not quite how I had planned it, but hey.

I'll know for next time and will go down the aftermarket route.

Thanks for all your help guys.