
Because of the help and the comments here I WAS able to get my model of the Dunsmuir Engine Shed imported successfully into Railworks! The only thing that I "THINK" I did differently was I went all the way back to Sketchup and selected all the groups and made them into a component. I then exported the model as a .3ds file, imported it into 3D Crafter, textured all the surfaces I could see, merged all the groups and meshes into one group, assigned textures to any surfaces that could not be seen, ran the "Train Simulator Wizard" up to the second screen and then finally exported the model as a intermediary geometry format. In Railworks, I created a new blueprint and exported it. In the Asset editor I was able to preview it. In the route I was able to see it.

However, there are STILL two problems with the model. One is not a deal breaker but the other one is!
1. The model when placed in the scene starts out sitting about half way in the ground! This can be adjusted, I suppose but I had set the X, Y, Z origin of the model in 3D Crafter to 0,0,0.
2. The model is not the proper size

. In Sketchup I had made the model 151 feet long, 45 feet wide. Now, using the 100' turntable as a guide it looks like the model is only about 80 feet long and about 20 feet wide. This is a deal breaker.