I downscale and simplify the original model by BrittLiv with Blender then apply a Boolean difference modifier with 6 cylinders and "voila" : a nice pe...n holder for my desk !
On the picture, I downscale at 85% and it is still ok for the thinner pens.
For larger pens, keep the scale at 100%...
You need support for the chin and the top of the hood.
You need to fill it a bit for the cylinders.
update : I post a second model ok for empty printing but still need support.