Thanks to Tux-Mania for the original design. I altered the original pins that held the raspberry pi with screw holes. I also removed the logo from the case top and added openings for GPIO access and a 40mm fan mount. Using this design for a ceiling mount for an old Raspberry Pi I had lying around to use as a smart garage controller. I'm not 100% certain the mount for the fan is completely accurate, took the measurements from an engineering design of the fan I have on order. Will update if any changes are necessary. Fan will mount outside the case blowing out.
UPDATE: You will need to adjust the mounting holes for the raspberry pi model B. They are slightly off. If I get a chance, I'll update. Right now it is mounted on the ceiling in my garage and may be a while before I remove it to update (it's my only older Pi model b). You can get small screws in, but it's not as perfect as I would like.