Dell evidently ships these GPUs with a short (2U) bracket attached and nothing else. They will then instaclose any customer service requests after replying with some “contact Dell sales” copypasta.

I made this because I needed it - and I guess on the off chance that it helps one person… here it is.

Design based on 3D scan of 2U bracket (for measuring Intel's mounting hole location offsets) and the PCIe spec, specifically “PCI Express Card Electromechanical Specification Revision 3.0” figures 9-5 and 9-9. 

The item pictured was printed by JLCPCB from steel for $8. 

You can't print a functional version of this from plastic, sorry - PEKK-CF or higher tier stuff maybe, but even if it's strong enough it won't tie the card to chassis ground. The model is not designed for FDM printing in the first place. SLS/SLM is the way.