Slim spool holder for original prusa mk3 double spool holder

I've a lot of filament with narrow opening for spool holder.
So I've removed original spool holder part from the one side and mounted mine slim version.

What would you need:

* Some M6 threaded bar
* Some bushing with 6mm hole inside, length should be 1cm-1.5 cm shorter then ro , from both sides.

Make:
1. Clean key (teeth) on the top of printed part named _key_. There could be some hanging filament, when printed unsupported.
2. Screw one side of the rod into the _key_
3. Slide bus