First I would go with the more saturated colors of the preview from blender.Then you might want to think about what story the surfaces should tell. Are they clean, used, weathered, etc. Out of which material? Surface finish?Currently it's too much randomness - cloudy spots everywhere.
doing a bit more detail work
I made it from a reference. I link it in my artstation page.The concept art itself is only color shading so it is hard to judge the material use but i plan to go for a realistic texture.
You are so awesome man, going above and beyond.I will definitely go back to redo the texture at some point, since i plan to redo the design a bit. I was a bit too rigid before and try to follow the concept one for one and there are many things I miss.Here is the modified version. I made the binocular more compact, I realize the glass is suppose to be almost flat instead of that weird globe shape I had. And the little wire at the end there is i think some sort of light signal instead of something attach to the helmet.