I did sketchup before and I know the program is kind of simple, but more than a textured box would make a better ring. I'm sure you could use cylinders. Use em'.
Sketchup can only do a fraction of what 3ds max can do. Majority of industry developers would laugh if you suggested using it to produce assets for a game. But its capable of geometry much more complex than that. I used sketchup to ease my introduction to 3d modeling, so i support his efforts. Texures look good, well... at least for a 1996 n64 game with 8mb of memory.
Actually, in my opinion, the textures, the normal maps, and the specular maps make or break the quality of the model. You can change up a stupid old plane model to make up a realistic grass plane. I do have some examples of sketchup models I made a "next-gen" effect on by just playing with my textures and pushing the limit with the map use.