Third test print:
- Recessed the swoop around the knob.
- Made the entire thing 1mm thinner so that the bottom button would protrude a bit more.
- Made the button holes smaller.

And this one has more problems:
- The left/right buttons STILL fall out. The plastic has as much as 0.4mm shrinkage in the final print, so I keep overestimating how big the button holes have to be.
- With the thinner fascia now the four screws don't sit all the way down, so I have to make them sit up in little protrusions like the original fascia.

So I'm going to do those things and do yet another test print, and if the button holes are finally fixed then finish it up with the two versions (flat and beveled).

Pretty happy with the looks of it overall though.