After quite a long time and several setbacks, it's finally finished.
The buttons in the front turn the VU meters and LCD on and off, and there's also a (red) shutdown button.
When the RasPi has shut down completely, the LCD and one of the red LEDs turn off, so you know it's safe to "pull the plug" - i.e. turn the whole thing off using the original "power" button. There's also an IR remote, plus all the usual stuff....
I'm quite pleased how it turned out
Here's a short video of it in action:
https://www.youtube.com/watch?v=4MDzo0v2abI
