I've created this Hydrant based on CGcookie citizen tutorial to improve my baking skills, In the Zip file you will find AO, Normals, Textures, Full render baked out.
The low poly version has 500 polys, High poly 70k.
There is one issue, I don't know how to fix the AO map, especialy screws at the bottom of the model. Any ideas?
Your UV map has 2 parts that are overlapping. thats why baking them turned out wrong (The tips of the 2 small arms). the reason why the bottom of the model is not affected by baking is easy. its not unwrapped so they don't appear in UV map and you accidently deleted the bottom parts of the rings. Turn your camera so you see the mesh from the ground, you will see. First Complete the Mesh (fill the Holes), then unwrap the LowPoly again. now you can bake everything again and it will look better :-)