Volantex Phoenix DJI O3 tail mount

the upper part also works with my base for the AtomRC swordfish:

https://www.printables.com/de/model/977779-atomrc-swordfish-dji-o3-mount-v2

the upper parts are actually identical
 
Requires at least 4 5x5x3/5x5x5 neodymium magnets for Volantex Phoenix version; 8 is better.
Attach to tail fin using double sided sticky tape for example.

Camera can be mounted with original screws, antenna clips into place.
The case/pod offers some kind of protection against impacts following a crash and if magnets are used for mounting, chances are good that the air unit just flies off instead of tearing camera, antenna and air unit apart when everything is attached directly to the vehicle.

Orientation should be fine for printing.
Supports needed for both parts.
Make sure that only those areas needing support are supported.
The pockets for the magnets DO NOT need support for example.
Make sure that your bridging and support settings are tuned well enough.

The magnets are press-fit post printing, keep an eye on the correct orientation as they're not (easily) removable.
Your printer should print dimensionally accurate or slightly oversized.
Adjust xy-compensation or scale model if needed.