I finally found the idea. First I will be using the JLCCNC cnc turning fabrication from aluminium. Second the idea is I will machine the pen and then make a M5 hole into it which will cover the hole + hold the clip from sheet metal that I will be bending with the help of a 3d printed bending guide. I hope this will work and I do think It’s a good idea, but first I’ll print this prototype :).