9/3/17 Based upon feedback from others, the Core was too thick, I reduced the z-height size to better match the cover pieces. Replaced the core with a v2.
Look at https://www.thingiverse.com/make:378307 to see the one I made and am now using.
I am a fan of Sneakypoo's Earbud Holder (http://www.thingiverse.com/thing:36321) - it works. Only problem is that my current ear buds don't fit or work with the core design.
Having just seen Nikolaev's design (http://www.thingiverse.com/thing:2156648) - it is too short and small for my needs but has potential.
I decided to make a compatible core to Sneakypoo's design, inspired by Nikoalev's design, that uses the legs from Sneakypoo's design.