I had a look at it, and for some reason that site didn't allow downloading as an .STL. I downloaded it as a Collada .DAE file, which Shapeways can understand. It was able to take the file and set it up as a printable object.
The question is, is it printable at the size you want? Making it at "2700 scale" isn't a very meaningful request. Even though it's got a human figure for scale and you can guess what the intended scale is, I have no idea what you think is the right size for this thing! I'm presuming you want to use it as a detail part for an existing model, so you'd need to figure out what dimensions in millimetres are required.
Anyway. The basic problem with this particular design is that the guns are hollow, which makes them very thin and weak. That's fine if you want a large model, but at 1:2700 I'm guessing we're talking a tiny model that wouldn't be printable. So you need to convert the model into one with solid, perhaps thicker, guns, depending on the final size you want it to be.