Finished my ST C39-8s this morning. Mind you these are the first locomotives I have not had to add any details to since I started detailing units in the mid-1980s. Out of the box these units are fantastic.

The only thing I did was to weather them. I liquid masked or taped off the glass and lights, then applied an exhaust of 10 parts black to one part dark brown with an airbrush on the roof. I did not like the light gray look of the various air intakes on the front half of the unit so applied some Tamiya black panel wash to the grills, but that didn't quite do the trick. So after that dried I applied AIM Dark Gray weathering powder to all the grills on the units -- front and back. Then AIM Black powder on top of the unit in the radiator panels. I then airbrushed a custom mix of Model Master Leather and Skin Tone Dark Tint (about a 2:3 ratio). Then applied the Dark Gray powder to the walkways and steps. And sealed with MM Flat Clear Laquer (and removed the masks).