The railway station was done – well – almost. Some light was missing. I had some brass tubes left from a renovation and some white plastic balls from a defect light chain. The plastic balls fit perfectly into the brass tube and a 5mm LED is fitting into the balls. So the only thing that was missing was a little bit of electronics to connect the LED to the 18VAC rails. Just a 1k resistor and another diode solved it. So just a few cent of investment to build some nice lamps for the railway platform.