I like this but there is a lighting error and I have a suggestion.
First, the shadows on the screws are the opposite of what they should be so the gruves look like ridges poking up. Second the rust is a bit too regimented. You might want to experiment with some blur and/or the smudge tool. Put the rust on a separate layer so you can fool with it. Actually one technique to make the rust look better is to add a tiny bit of noise to it. Also the color of the rust isn't quite rust color, make it a bit orange-browner. Right now it looks more like blood. All this said, I think it's a cool idea.