My external USB SuperDisk drive came with a broken eject button. It would push on a button on the PCB if pressed, which (I presume) would unmount the disk and trigger the automatic eject function of the drive. But the back part of it that pushes down on the button was missing, and instead of recreating the intricate mechanism, I decided to simply make using the mechanical emergency eject easier. After all, if the drive is connected, it can be ejected via the computer.

I printed the button lying on its back in PLA, and it slides onto the drive hook firmly and easily.