Nice pen, the satin parts really look nice with the cofee blank.
The best way to finish the coffee blanks is to;
Turn with sharp tools, then when you are almost done turning dribble some thin CA on the blank (with the lathe off). I use one of those plastic bags where the pen parts come in over my index finger and hand turn the lathe while moving the CA all over the blank ...then let is soak in and set. Then turn just a hair and repeat the ca step. What this is doing is sealing any open pores on the coffee beans. Start sanding and sand (I start at about 320-400) up to about 600 then do the CA thing again. Then start again at about 600 and gently sand to your normal sanding routine. At this point you should do whatever finish you normally do. I always do a CA finish bec It is easy for me and it is really durable.