Made the backplate today.
Started out with a quick test run on a square bit of aluminium I bought. Turned out very good so moved onto the main thing.
Marked the holes and clamped it in place
Steel vs Aluminum is like taking candy from a baby.
Used a wood countersinking tool and a screwdriver to create the countersunk holes. Using a drill with the tool caused burrs that would have to be dealt with.
Final result was a little wonky but I am not too bothered.
However the issue was how close the backplate was to some of the components on the back of the soundcard.
Fortunately I bought an A4 sheet of vinyl to cover the tiny orange squares on my SSD so had loads to spare.
I'm actually a tad bit annoyed good my signature looks as it is going to be face down.
Surprisingly it still works.