The replacement lamp for by Railking house would be:
431 Clear, 14 volt, G 4-1/2 Globe, 3.5 watts, miniature bulb Ba9S base
You would have to check the auto parts store. I don't know about their stock.
Power a 14V bulb with 16V and the bulbs almost last forever.
With my calipers and the bulb out of my house in hand I went to this site
Visual Bulb Finder http://autolumination.com/visu...ulb_finder_ba9s.html
The toy train incandescent and led bulbs are listed her
Toy Train Light Bulbs http://www.autolumination.com/trainbulbs.htm