Thank you for all the kind comments and likes.
The ambient lighting (including the starlight) and the ambient sound are all controlled using an Arduino Mega. The more I delved into Arduino the more possibilities I discovered and I've been spurred on to make progress with the random shunting order generator which is initiated from a small (320x240pixel) touch-sensitive LCD panel mounted into the front fascia:
View attachment 118007
Pressing 'Start' generates a random shunting order for 5 wagons which is displayed on the next screen:
View attachment 118008
As the wagons are shunted into the correct position, they're marked as such using the touch-sensitive screen:
View attachment 118009
And once all 5 wagons are marked in position, a new random shunting order is automatically generated:
View attachment 118010