I decided to use CAD and a lasercutter for the train carriage part of the scale model. This was because the design contained a lot of small and repetitive details, often involving curves. I copied the style of the carriage from the recently restored Met 353. You can find out more about the restored carriage here.
I used Adobe Illustrator to draw up the structure in 1:50 scale and then put A2 mountboard through the lasercutter. I also used the same process for the doors, collapsing stairwell and other small details.