Note: the details of fitting to a frame are currently untested! To complete the N scale U18B you need couplers, a frame to mount it to such as an RS3, fuel tank (sold separately), and handrails. For handrails, dimples are provided for drilling holes for Gold Medal stanchions, or you can download this 3-D printable handrails file, upload it to your Shapeways account and order them using the “print anyway” option at checkout. The 3-D printable handrails are too delicate to sell directly. If you would like a dummy model, choose the dummy version. You'll have to figure out how to get the shell to fit a frame and accept the fuel tank.
3-D printable handrails file download:
https://drive.google.com/file/d/1kGLXc5V5ovs6uJXMUk3HH5Ad5RlqfMCp/view?usp=sharing
Fuel Tank:
https://www.shapeways.com/product/PFRY2R7QR/ge-u18b-n-1-160-fuel-tank-2-pack
Dummy Version:
https://www.shapeways.com/product/27X74H3KN/ge-u18b-n-1-160-dummy-locomotive