A couple of easy options are to make the pen without a centerband. All you have to do is make the upper barrel a little longer. You can do that by using the long tube from a euro kit, or seat the tube on the cap end and leave a gap at the centerband end where there is no tube. That probably doesn't make sense, but there are better descriptions in the tutorials. You just make the upper barrel a little larger diameter than the lower barrel. Another option is to use something like corian or pickguard or a different color wood. Again, you can use a euro long tube for the upper barrel and trim back about 1/4" for the new material. I've done this with corian a few times and it works pretty well. Again, there are lots of tutorials and posts with better details.