It would appear that my model is suffering from multiple problems. I am proficient in Illustrator and Sketchup, but Blender is a bit overwhelming my first time in. First, the main logo consists of just under 300K vertices, most of which are completely pointless. Is there some tool I can use which will automatically eliminate vectors which do not create an angled face? Second, I followed the tutorial to resolve the non-manifold error, but my entire model (all 300,312 edges) are selected. Perhaps there is a tiny hole somewhere in my shape, but I can't find it. Is there a script or easy means to locate that? Thanks!
Okay, despite being pretty sure I'd removed duplicates once before, did it again and reduced the model down from 300K edges to 19.5K edges. A significant improvement, to be sure. I suppose now it is not as essential to reduce the number of worthless polys in the main logo, but it would be nice. The non-manifold bits left over are a gnarly bit of nearly hidden shapes that I could just as easily do without.
Here's your main problem. Red indicates flipped normals. I've attatched the fixed file for you, but I still think it'll need some work. A lot of your conversion artifacts are quite small and will probably flag the shapeways systems for minimum feature size. I recommend exploding your model into shells, deleting all the unnecessary junk, and then boolean everything back together. Also, converted your model to mm.