Fan section for MultiPi Raspberry Pi Cluster Case

Jesse76 has designed a great Raspberry Pi cluster tower, missing, in my opinion, only a section for a fan. I've designed one to address that minor issue.

This is a remix - I pulled jesse76's original no-vent lid into OpenSCAD and proceeded to do horrible things to it - cutting and stretching and drilling - finally assembling the ragged pieces into a working fan section. Jesse's nice "Multi"-(pi-symbol) logo survived the process intact.

I made one each for 40mm and 50mm axial fans with an