Here is a translation of
@jick wu's reply above, using Google Translate. Original was found to be Chinese. He/she was responding to my question, "How did you finish the ebonite?"
"Yes, it is processed like other resin materials, but its hardness is higher. It is easier to obtain the required hole diameter with a carbide drill. Different drill bits will be replaced on the conical cap. Of course, there will be high and low steps inside. The price of the whole pen is 350 US dollars, so I spend more time on fine grinding and turning. I use warrior sandpaper (120-3000 mesh) to polish with water, and then polish with cloth wheel polisher and Mingshi purple wax. It is very important to choose a flannel wheel, otherwise the pen holder will not shine."