How to reassemble Disc Drive Spindle?

I have a gamecube that is fully operational, albeit the disc drive spindle is taken apart.

I am looking for a complete parts list to make sure that I have all the parts required to put the piece back together.

So far I have the following:

-3 ball bearings

-1 "push" button

-1 spring

-1 back plate w/ grooves

I can't help but feel that I am missing the part that the spring engages with to release the disc from the tray.

Any help is appreciated.

Thank you!