There are many ways to get this acrylic shape with the various mounting holes. You could use a CNC, laser cutter or you could cut it using your preferred power tool. The DXF file is available on Printables or directly below.

The piece of aluminum extrusion serves two purposes: to mount the electronics and to counter balance the servo motors. You'll want to cut your piece of extrusion to 13.5 inches (34.29 cm). Aluminum can be cut easily with a miter saw.