The panel is split in two parts to allow printing on reasonably sized print beds.
The snap lock pins are printed separately for better strength. They need to be glued to the panels.
Note that the case of which I took the measurements is from 2017 and the manufacturer might have changed the design in the meantime, so please double check that the holes in your case match the position of the pins in this panel before printing.
The author marked this model as their own original creation.