I glued the tube into the tube holder and then I glued the speaker head on top of the tube. Picture 1 to 3

Than I glued the panels to the base plate and the tube holder. Picture 4.

I mounted the electronics inside the case and connected a 12V power supply via the switch to the LED in the tube and the radio electronics.

Then I mounted the knobs to the potentiometers.

I used a 50cm piece of aluminium as the antenna and mounted it on the back.