I made one with sunken screws and nuts. It looks good, as good as my current design. But it required gluing the top 2 layers, the middle 2 layers, and the bottom 2 layers. I made a mess gluing them and it took a long time for me. I could ask the shop to do but it would cost more labor.
My current design works pretty well. the case is actually thinner than your regular Filco case. So even with exposed screws, they don't come up very high. If currently your palm or your thumbs touch your keyboard's case while you type, then the screws might interfere with you. But if you do type like that, you are doing it wrong :-).
KL, you got PM.