Dell 3.5" HDD bracket vertical mount

I have designed this for my Dell Optiplex 390.

I wanted to install my large PCI GFX card into my new computer. The original HDD mount was in the way for the end of the card and it's power supply plugs.

This is designed to be mount to the inside of the case with 3mm (or larger) screws with a lower mount that rests on the inner casing.
The universal bracket is deigned to slot into other but will need gluing to make the parts solid.
I have designed a spacer for the HDD that will fit thinner