I'm into all things hardsurface so your instrument keyboard stoodout for me 😎 Also, perhaps think about including the materials and/or props you've already made toward creating a diorama or game level environment.
Even though the challenge is already done I wanted to tackle one of the hardsurface props. I'm learning on how to work with zbrush more to be included into work flow I currently have.
This is also super important now that Boolean operations are more stable across most 3D modeling software. http://polycount.com/discussion/168610/proboolean-dynamesh-hardsurface-workflow-tutorial
I'm no hardsurface wiz but your edge flow looks kinda bad. I suppose if it bakes down fine then it shouldn't be a problem but it's good practice to have clean geo regardless.
I have to say that, that is the coolest hardsurface ive seen. the style of it is so interesting to look at. (the top image of the detail is my backround :) ) cant wait to see more! definitely subscribed.