Hey there,
made a few holes too much, expanded it into a window and now added a printed cover on top.
Easier to show in pictures:

- gbfin.jpg (103.39 KiB) Viewed 3737 times
Expanded into big "window" :

- gb5.jpg (78.46 KiB) Viewed 3737 times
And covered with 3d printed part:

- 3d.jpg (90.11 KiB) Viewed 3737 times
The part, made in SketchUp:

- fan.png (42.29 KiB) Viewed 3735 times