I have included the Freecad file incase you want to modify the design. I used 6 2mm socket head cap screws to mount the caps to the main frame. The mount holes were tapped prior to mounting the endcaps.
The Freecad file contains a master Sketch, should you decide to modify the design us it as your starting point as many of the body sketches references it.
The author remixed this model.
The case is slimmer as the endcaps transition smoothly into the main body. In addition, I have added a mount which allow me to couple the display to my printer magnetically.