Sharpie makes a 'high-end' pen that uses a replaceable cartridge. If you do a search on this board, you will find discussions about turning bodies to hold that cartridge.
I've tried to do this, and the basic turning is fairly easy. The challenge is that the replaceable cartridge is design to screw into the Sharpie body using a proprietary thread, and there are no standard taps available that match that thread. As I recall, it is possible to 'special order' an appropriate tap, but for cost reasons that only makes sense if you intend to make a bunch of these, and almost certainly is not a practical option for a gift for Christmas 2017.
An option to at least try is to create molded threads inside the turned body. Turn the body with an ID that is as close as possible to the major diameter over the threads of the insert so that the insert fits snugly into the body. Wrap the insert threads tightly with teflon plumber's tape, and apply a coat of epoxy or thick CA, and then slide the insert into the body and allow the glue to cure. Later, after the glue has cured, unscrew the insert and remove the remnants of the PTFE tape. The cured glue inside the barrel should be a close match to the threading on the insert.
You could just glue the replacement cartridge into the turned body (make it a disposable pen). But if disposable is OK, then you could accomplish the same thing by simply turning a sleeve to glue over a standard disposable Sharpie pen. The clip on the standard Sharpie might be in the way, but its easily removable.
