I was unable to find a model of this specific design to match my existing slot covers.
I previously downloaded a cover from this great collection https://www.printables.com/model/219169-pcipci-e-slot-covers-10-designs but realized the design did not match as closely as I initially thought (see the top three slot covers in the 1st and 3rd images).
I designed my own based on the couple of existing slot covers that I have. (I bought the case second hand so it was missing a few).
The author marked this model as their own original creation.