Hi Don,
I googled it,and it looks like it's the rollerball refill for the Pentel Easy Roller pen,which looks like it's an all plastic pen,with the refill being half the pen,& a body that screws onto the refill,looks Bic-like.
I wonder if you could make the body section out of wood if you could get a coupler that fits the refill,or cannibilize a new Easy Roller pen for that part,and maybe make it's body closed-end?
Just throwin some ideas out there,I've never ventured into making something custom like that,but I'll bet you could!
Steve