Pen holder for Summa D series plotter

This is a pen holder for the Summa D series plotters (D60, D120, etc).
It is thought to carry a standard BIC ballpoint pen without its outter plastic shell. It's a press-fit so no bolts necessary, however, you'll need to play with the tolerances. The attached design has a 4.2mm hole diameter, and the standard BIC pen part that inserts into the holder is 4mm in diameter.

No supports needed when printing with the attached STL's orientation.
I'm also attaching the F360 file, in case you need to modify anything or improve it (for instance, by adding a nice lid)