I completed the locomotive and the lighting works now.
To increase the variety I have provided under several colors to choose from. Adding a different color to the group_0 under the TG "vis / Sketchup2" in conjunction with the "specular" or "glasHell_difuse" selection in the MaterialEditing field in the "Gloss Map" field produces many color shades.
But it can happen that colors other than these can lead to incompatibilities in the appearance of the model.