I bought a Cooler Master Masterbox Q300L with the express purpose of modding it. I love how the case looks without the plastics. Looks industrial. I'm in the process of making replacement parts for it.

This foot snaps in just like the original, but has a 3mm screw hole in the bottom to tension the flanges that grip the bottom hole and hold it in place. You don't have to use the screw, it just worked better for me.