Great model but Sketchup is not great for detailed models like that. Sketchip is horrible for UV mapping so the models don’t look that hot when imported into an engine.
Although they are acceptable for simple geometry like buildings and bridges. I used some sketchup models in a custom level ( the bridge in particluar ) I made using cryengine. They are acceptable but if there were anymore detail then I would have used model done primarily in 3DS Max.
You can see a video of an earlier version of the level below:
http://www.youtube.com/watch?v=b39GB-PJq7c
But apart from that you have some real skill. Maybe you would consider joining my small team in making a showcase level for a thoughtful tactical shooter ( not COD based ).