This design is basically a mashup of two designs:
RaspberryPi 4 Case for Prusa i3 MK2S and MK3 by mpkottawa https://www.thingiverse.com/thing:3952065
RaspberryPi3 Mk3 Case by agarajag https://www.thingiverse.com/thing:3004038
This enclosure makes it possible to mount a Rasperry Pi 4 with a heatsink with a fan (by GeeekPi on Amazon) on a Prusa i3 MK3.
The author hasn't provided the model origin yet.