I went looking for a PanelDue 7 case and mount for 2020 rail, but was not happy with what I found, so I designed my own.
There is one version for the old PanelDue (with the separate LCD) and two 7i versions, one with a reset push area and speaker holes and a version without those features.
Neither version is designed to allow the use of the SD card slot on the PanelDue.
Since I don't have a 7i, let me know if you run into any issues or if I need to change the design.
23Jun19 Update - Added a Railcore II mount for 1515 extrusion, it holds the PanelDue at an angle - suitable for standing next to a Railcore on a workbench.
Back: Drill out the corner holes with a 3.5mm or 1/8" drill to provide clearance for 3mm (or 6-32) screws. Six blind holes in back are for the Back Mount - drill them with 2.5mm or 3/32" drill. then tap for 3mm or 6-32 screws. Determine where you want your wires to exit the housing and drill an appropriate hole in the back or side. Make sure you're not drilling where the Back Mount will cover.
Front: Drill all posts with 2.5mm or 3/32" drill. Tap 3mm or 6-32. There are 4 posts for the LCD and 1 post for the PanelDue. Secure the PanelDue. Screwing the Back onto the Front will sandwich the LCD between the bosses with the screws.
Back Mount: Drill 4 mounting holes 3.5mm or 1/8". Large hole should be clear for a 1/4-20 or 6mm bolt.
2020 Mount: Remove supports. Mounting holes should be clear for 4mm screws to mount to 2020 extrusion. Large hole should be clear for 1/4-20 or 6mm bolt.
Put together with anti-rotation lugs on Back Mount and 2020 Mount engaged with each other. Use a 1" long 1/4-20 Wing screw and a standard hex nut. 6x25mm wing screw and nut could also work.