Consider making your own centerband out of contrasting wood. I take a blank and drill the 7mm hole through it. I then use the bandsaw to cut the blank into 3/8 in pieces. I will do this for several colors of wood.
I then mount the pen blanks normally and turn them to round. I cut a tenon into each blank on each side of the center bushing of around 1/8 inch. I cut the tenon down to the brass tube.
Remove the blanks and select a contrasting piece of the center bands you prepped earlier and glue to the clip end only. Reassemble the blanks on the mandril without the center bushing and make your pen.
When I cut the tenons I cut a bit into the wood so I can get a good fit with the centerband.
