DIY Trammel and Lathe Test Rod

I needed to adjust my drill press - I knew it was out of alignment, but I did not know how far it was out.  I made a trammel about a month ago.  I had to make some adjustments on it today, because the dial gauges would not stay on the drill press table.  That +/- 0.2" on each side of the drill press was bad, but it was still a guess.

I drilled two more holes for the dial gauges, cut some slits with the bandsaw, and re-installed the gauges.  Then, I threw it into the drill chuck and re-measured the drill press table. and that guess was pretty accurate.  So, I put the table at the high point, loosened the underside bolt holding the tilt just a little, grabbed the 3 pound shop hammer, and just gave a couple of light whacks at the table.  I got the drill press table to within 0.0005" (seemed like 0.0002", but I always err on the side of caution) :

So, my drill press is now calibrated and pretty much level.  I'm stoked about that one!  Next, since I had the drill rod left over from doing the trammel tool, I cut a length of 12" off, and faced and center drilled each end.  Then I stuffed it between centers, and used the law of averages to center my tailstock with the headstock.

I was about 0.020" out of alignment, but now I am only about 0.002" off.  Not sure I can get that much better, but I may try as I feel the need to distract myself.