I have changed my approach to the Dalek ears and got some translucent filament so I could put a LED at the bottom and light.
Below are images of the ear the first being a prototype of the ear, in this design I added a tube with an opening at the bottom and an extension.
The intention was that would fit into the dome this was my first attempt and I used regular white filament.
My second attempt was to remove the extension and made it an indentation with a wider diameter.
The final image is the same second attempt with it inserted in to the ear cage.