If you use fusion360 you can import the f3d file and use the Parameters to generate a unique size reader to fit any printer and align stuff inside the reader.
the STL files provided here are 245mm at the widest, this should fit on a prusa printer and most other slightly larger printers.
I would say try printing the first layer of the top to test out button fittings. If they don't fit you can scale the stl files (Not recommended because it will also scale the screw holes) or you can change the values in the f3d file and re-export the files.
The screws are m3 (3mm) and you don't have to put them all in! It's way over kill and took forever to get them all in there.
The author hasn't provided the model origin yet.