This model is remixed from:
https://www.thingiverse.com/thing:2917729
The TUSH spool holder is here:
https://www.thingiverse.com/thing:2047554
I found out the hard way that it barely didn't work on my printer, and decided to at least put the wasted filament to use to figure out how the model would need to be changed. It's not a perfect edit, but it works well.
I printed these in Cura v4.11.0 with a .2mm layer height and no supports. Ironing (the setting, not the clothes cleaning process) really makes them a lot smoother and nicer-looking. Important note: the bracket should be printed four times: two as it is, and two mirrored for the other side of the holder.
The author hasn't provided the model origin yet.