Looks like OO so for 28 mm it would be underscale for a main line. However for gaming purposes it could be OK since buildings, etc tend to be underscale anyway. Or you could just have it as a narrow gauge line - there were many industrial type lines across Europe during this period.
My advice would be to paint the tracks rusty. The side of the rails would be rusted with only the tops shiny. You can paint the whole rail then get a piece of hardboard and rub it along the top of the track to remove the paint to give the shiny top. The ballast is rather clean as well - some additional weathering on that would make it look even better.
Overall though looks good - nice and flexible.