Hmm...not sure what plane / engine you're dealing with but maybe something like this would help:
http://www3.towerhobbies.com/cgi-bin...&I=LXD636&P=ML
I know you're in the UK but maybe Dubro products or something similar are available there? I believe this is just basically silicone rubber - I'm sure someone will set me straight if not...
Regards...