There's been quite a few requests on the Onion Omega community board for a minidock case, since so many already exist for the expansion dock. I haden't seen one surface yet so I took it upon myself.
I've printed a couple so far in PLA, with the stock printrbot settings in Cura (50 speed, 15% infill, etc) and they've turned out great.
I mocked the whole thing up in Tinkercad after taking some rough measurements and it seems to work. I initially had the mini USB port too low, but after adjusting that it seems pretty good.
I'm still not super happy with the slide in lid. I had to do some shaving on it with a razor post print to get it to fit, but that was because of some warping.
The case it self holds the omega just right, and keeps the pins from being fully exposed so a lid isn't really super necessary anyway.