Build Instructions can be found on the Pixelmatix Docs site
You don't need a SmartMatrix Shield to assemble, you can follow the schematics and wire a Teensy 3.1 directly to a compatible LED Matrix Panel using 13 wires. Don't forget to connect the Latch signal to both pins 3 and 8 on the Teensy. The buffers in the schematic are optional depending on the panel you use. Some are 3.3V-logic compatible so the Teensy can drive the panel directly. Others need closer to 5V so a 74AHCT buffer powered by 5V is needed between the Teensy and the panel.