The weathering on the droid is spectacular, very realistic and very believable. Your worn steel and smoke/soot areas are great, the chips are very nice. You could very likely produce some impressive armor builds. 

In all Honestly, something about the gun seems slightly out of place to me, I'm not really sure what but I think it's a lack of wear or it's just a bit too clean?

 ???

*I am not trying to nitpick or be overly critical of an otherwise stunning build, I am not in anyway intending on ruining anyone's fun, it's just my opinion.