The MiSTer Pi has taken the MiSTer FPGA world by storm, it significantly reduced the price of entry into FPGA Gaming and naturally brought a lot more users to the niche. There have been a few cases made for the MiSTer Pi, some from Retro Remake (the company behind MiSTer Pi) themselves, as well as some from third parties. You can either get the 3D print files and print a case yourself, or you can buy a pre-made case. Some case designs are free to download others charge a premium, sometimes for a period of time. The Retro Enclosure for MiSTer Pi (Multi-Styles) case design is currently purchasable via pinshape.com. So if you have a 3D printer and want this case then you may wanna check this out.
https://cults3d.com/en/3d-model/gadget/retro-enclosure-for-mister-pi-multi-styles
