Whipped up a few sets of barrel spinners when my old cast aluminum bearing cassettes developed a crack. These should last till I'm too old to do this stuff anymore.
I have one of those, only I like the tips (that go in the barrel and camber) made out of hardwood dowls. They dont work as long, but they are easier on the crown.
That set up works great used on a belt sander, working your way up to 2000 grit you can put a mirror finish on a barrel.