An easy way to enhance the look of any diesel locomotive is to blacken the grills and vents to provide more depth.  You can use a black wash to bring out the grill or vent details.  Weathering powders are extremely effective bringing out locomotive vent and grill details.

Here's video of my layout, first in near-total darkness, then in daylight. [video:http://www.youtube.com/watch?v=cLmc2DIJHkY 100x100]

I've finally added as much plaster cloth as I expect I'll need, and have moved on to priming the base before painting it.  Priming made it look unfamiliar, [ ... ]