I have constantly wanted to have a BNSF Dash 9 H2 in Railworks. So I downloaded the pack from Trurails simulations, and put in the engine and cab shape files of Donner pass Dash 9. The model loads but is in a very "gliched" state. So maybe someone knows how to fix this, or could even provide the engine and cab shape files.
Im pretty sure it's considered piracy if anyone provided the geo files for a dlc to someone that doesn't own it.
For this, to work you need the Dash 9 pack from Steam. If you live outside the USA you won't be able to purchase it. This repaint comes with a manual so open up the download with 7Zip to read the manual and it will explain everything.