This type of enclosure is built around "SoftRF Shield Rev.1" and fits typical 2.25 inch (58 mm) hole of an aircraft instrument panel.

3D print four STL files from this folder. You may pick some printing advisories on my Thingiverse page.

Fasten printed parts with eight 2.5x10 mm screws. PCB is secured to the shell with M3 screws and nuts. Battery compartment is attached to rear panel with a plastic glue. Cover keeps battery from falling out.