If you're tuning with points, do you have a good dwell meter? I once tried 3 dwell meters on one car and got 3 different readings. (To make it even more fun, the distributor was missing one of the adjustment screws, so I had to wing it while adjusting it.) I since got a 4th dwell meter so I could confuse myself more. The old school dwell meters are NLA. I might eventually break down and buy a Fluke 88V. I think it will measure dwell, and I only have about 8 or 9 multimeters, so there is a need to buy another meter.
Once you switch over to an electronic ignition, you can probably retire the dwell meter. Sometimes I still work on a luddite's car, though, so I'm keeping them around.