Blender Internal
Hi there, pretty good start. I esspecially like the part, that’s directly pointing towards the viewer. 
The only thing I’d drop is the edge around the upper part of the of the key. I’ am pretty sure that it would look great without that edge as well.
Concerning the shader … You could stick with BI or switch to Cycles and use some curves for the r g b components to get a even more realstic silver shader depending on the viewers angle. Your final node setup could look like this: (be aware only the r curve is displayed) https://quaintproject.files.wordpress.com/2014/12/gold.jpg Visit http://refractiveindex.info/ for the curves of silver, but be aware of the wavelength of the colour components. Hope this helps to bring your image even further. Keep up your great work. Cheers Markus
Thanks for your feedback. I will try out your suggestions.