Oh that is really damn awesome! You've done it so well! I like how you have shown light on the piece, you've correctly shown that the piece is supposed to be made of a kind of metal material. The lines are neat and then are clearly showing where everything is and where thing are not. Proportions look correct too.
Maybe you could make it look better by drawing another one (or use the same one if you have a copy) Scan it in on the computer and then colour it on a program such as Adobe Photoshop and see how the final piece looks.