this one we did in signfoam. it was coated with luminore. I think we lost sleep over this one.
There were several made. the largest approx. 8x8
the train was fashioned after an actual scale train. the other 3d work was from drawings and photographs. We did all the files except had to have someone else to the train file.
This sign we was made approx. 6 years ago so i forget
http://www.luminore.com/
44490.jpg