Inwoods list them. I suggest emailing/phoning to check whether in stock or not.

http://www.inwoodmodels.co.uk.html

Also I think Slough Radio Control had them, though it is not on their website.

http://www.srcm.co.uk/

Otherwise just phone around the usual suspects: Sussex Model Centre, Als Hobbies, etc. I'm sure someone has one in stock.