Okay, I'm back. I just ordered a router centering tool like reible posted from Amazon for less than $11. 1/4 inch on one side, and 1/2 on the other. Man, Amazon is dangerous. You try to buy something for $11 then end up shopping for something else to get over $25 for free shipping. I think it's time to upgrade to Amazon Prime to always get free shipping - at least that's how I understand it.
Anyhow, this was my first try turning between centers, and it worked great. My mandrel has worked great up to this point, but it somehow got bent - either that or it's the divots left in the mandrel from the set screws on the 1/4" router collet chuck. I suppose it could have been the time I dropped the mandrel on the concrete garage floor. I have always held the mandrel in the Jacobs chuck, but one time I tried it in the router chuck. The measured runout was worse than the Jacobs (which was pretty much dead on - don't know why I even tried the router chuck - curiosity I guess) so I went back to the Jacobs chuck. Anyhow, the bent mandrel is what prompted me to finally try the cone drive and turning between centers. I went with the bushings for the first try. I'll try it without the bushings once I get a better feel for the pen kits I'm using and get better with the chisels.
I still need to cut down my second tool rest to be short enough.