I like the concept and idea behind it, but this looks more like a prototype than a finished pen. I don't like giving fluff comments so this is constructive. Keep going and see where you can take this design idea.
It looks unfinished in the last photo, but the first one has an interesting shape to it.
How does it look with the cap on? Like Tim, I think you've got an interesting idea brewing and with some continued work it could be very good.