So, i did it.
And it doesn't look half bad !
BUT, printer failed me again (or winter, it's really cold here) and the corners curled up again...
it fits, it just looks bad.
USB fits perfectly
and the battery + pcb of power bank
Also the power bank has button to turn it off/on, so the pin on the top works as that button !
A had few issues with tolerances, so i'll fix that in 3D model and then i'll send it to THE INTERNET !
ALSO, this isn't the final log, i still don't have the magnets so i cannot glue it all together. When they arrive, i'll glue everything to everything and do final touches.