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.

RSLaserkits Cheltenham Station Build by Modelersguild.com

If someone had told me two months ago, that there is such a thing as a Z scale Craftsman kit, [ ... ]

Adding Panel Lines to ACF Hoppers
Bill Mock
January 2010

Here's [ ... ]

 This is Micro trains Line SD40-2 Santa Fe model which I customized with working ditch lights.