At the recent Circus Modelers convention in Baraboo, one of the modelers was demonstrating a 3-D printer.
This 3-D printer uses a roll of plastic material that's laid down only in the project itself. Some of the items it previously produced are available for sale. There are wagons available in a variety of scales.
It takes a few hours for the figure of an air-calliope player to emerge. The printer, however, sells for about $1600. I don't know what design program the operator uses.
A finished air-calliope player (1/24 actual size) is for sale. In the background is a 1/48 wagon and team with a rubber mule assisting. Note at lower left a finished 1/87 air calliope wagon and team.