Thanks for the comments everyone.
Does the LED work? I've always wanted to do scenery with blinkenlights, never gotten around to it!
Yes it works, it was part of the packaging of a computer mouse I bought ages ago. When hooked up to the battery pack it gives of a steady blinking light.
I have wanted to do things with led lights for ages as well. With this project I think I must get out the soldering iron for the first time since school. I have one more ready batterypack with a string of lights that will be use for the main building.
edit:spelling