Basic PCIe cover based on PCI SIG 1.1 spec made in FreeCAD. 

The included .fcstd project is available for changes and adjustments to anybodys needs. Feel free to adjust the model to fit your specific PCIe card and its IO. Make yourself the specific bracket you've been looking for everwhere and couldn't find it.

IMPORTANT

The bracket has all of its dimensions from the spec, for 3D printing I'd recommend adjusting the thickness to at least 1.4mm to have at least some rigidity of the cover. Honestly 0,86mm turned out to be very flimsy, which is not surprising at all. 

Lastly the FreeCAD project attached may cause some experienced CAD designers heart attack and I apologize for that. This being my first published model, I know I have a long way of learning ahead. However it should be versatile enough to get the job done.