I really liked the PI3 case but wanted a more secure mount for the PI, the top bezel for the 5" display and an easy way to gain access to the SD card in the PI.
I added some vent holes to the bottom of the case, measured my fingers to see how big an access hole I'd need to re and re the Micro SD card.
A couple of tests later and version 2 has been working out pretty good.
There are two top bezels. One is labeled "relaxed" because on a couple of my 5" displays the TFT is actually over lapping the edge of the PCB board and there's no moving it. So I enlarged the area to give the display some "wiggle" room.
Update Sept 2019: Added variations of the top face. Now with bevels to allow better viewing. Look for the word bevel in the filename.
I always make the holes smaller than the hex head bolts that are going to fit in them. It's PLA for me so the bolt/screw will always create its own thread path.
I used (4) M3 x 4 to hold in the Raspberry PI and (4) M2 x 10 to hold on the top bezel.
I use an M2.5 and M1.5 drill bit to pre-size the holes so the hex head bolts will start in easier.