Thanks Radek, that explains why I couldn't find an image of it, the cover's gone! The anchor for the cover is a sort of key-hole but appart from that its much like the ones in your pictures, thanks
Bowie
I have attached a photo of the radio filter I have removed from my 42 GPW as part of its restoration, can anybody give me some info about this type as I can't find any reference to this design in my technical material..