There are plenty of available button boxes but none that I either liked or could build with the hardware I had at hand.

Also it is always good practice to model stuff yourself !

BOM

• 1 * Zero Delay Arcade USB Encoder/PCB (AliExpress)
• 12 * Arcade Buttons (AliExpress)
• 8 * M3 Heatset insertes
• 4 * M3x40mm Screws
• 4 * M3x6mm Screws
• 2 * M5x16mm Screws
• 2 * M5 T-Nuts

I chose to use this PCB as you don't have to do any coding and it's automatically recognized by a lot if not all video games.

PRINT SETTINGS

• 4 Perimeters
• 0.2 Layer height
• 20% Infill

The orientation of the parts allow you to not worry about anything breaking (supposedly) so you can use whichever material you prefer, although I always suggest ABS for everything :)

ASSEMBLY

1. Insert 4 heatsets inside the box (Base.stl) to mount the PCB
2. Insert 4 heatsets in the back of the lid (Lid.stl)
3. Mount the 12 buttons
4. Plug them into the PCB
5. Bolt down the pcb inside the box
6. Let the lid hang off the cables and install the box onto your rig with the side holes
7. Bolt down the lid by sliding the 40mm screws from underneath

Done !

If you want to make your own tags/labels I have included the STEP file for you to modify at will. 

Let me know if you encounter any problems.