Hate to be that guy, but the look of the surface detail really doesn't do it for me. The whole 12 layers of slap patch metal look doesn't do it favours. Also I feel there are many places a drawn on rivet or gear or turning mechanism would not go amiss. Also for the model your showing have some decency and blacken those bare naked edges.
I am well aware that making the templates for paper craft stuff like this takes a lot of geometry work and this one is pretty complex, but it could very much do with some more 2d art work.