I drew this out of necessity, as my other one broke. This normally has a very tight spring that goes in the middle and clamps in the wrenches, however I still have my spring, so I just totally disregarded it for this use. I think it will still work without the spring, but the wrenches would probably fall out if you turned the thing upside-down.
Giving this away for free, anyone can have this .stl, or .sldprt file, however please send me an email at paulbelcher@gmail.com if you find it useful. The text of the wrench sizes is all extruded from the face, which was painstaking. The "KC" in the middle stands for the college I'm going to, Kishwaukee College.
Thanks!