RC10 Team/Worlds rear suspension mount
 

Part number AS6360

It's the block that the hingepin goes through to mount the wishbone on the chassis
Hope that makes sense (tried to get a picture but my incompetance got in the way...)

Friend of mine broke one practising for the Swindon regional this weekend and is gutted, I've lent him one from my 10T so he can race :-) but he needs a replacement and it isn't made anymore :-(

Any help much appreciated.