The OMVS is a open source consolized MVS project by TaiToc Labs. I recently did a video reviewing the project here.
Avi-CE of TaToc labs along with Tian Feng have now made the files for the project available to the public under MIT License for the boards and creative commons non commercial license for the 3D printed case files. All that is needed besides these files and a way to produce them via printing and board production is a MV1C Neo Geo board, which can be found on places like ebay here.
I had preordered a OMVS to be prebuilt by TaiToc labs earlier this year and have been very happy with it. The paint job was ok, but I felt I could better fill in some of the texture and imperfections on the casing myself and wound up disassembling the unit and sanding it down, filling it, priming, painting, wet sanding, buffing and polishing it until it had a nice glossy look to it. With the availability of the 3D print files now it will be open for people to make modifications, easily print a new shell if they messed one up and just simply do the entire project themselves if they choose instead of buying the kit or assembled version, which still seems to be an option even with these files going public.
If interested in doing this project yourself, the files are linked below.