I plan to use my MFJ-945E antenna tuner in portable setup but it does not have any mounting hole. It has plastic side plates, so I decided to replace them with custom designed and 3D printed plates with holes and built-in M4 bolts needed for easy fixation in frame. It is snap in replacement for original plastic side plates.
Printed it in black PETG filament and it ended up looking good. Now this device is ready to be mounted in frame for my portable radio-station.
More details: https://www.thingiverse.com/thing:4524293