I just rebuilt a 7002A this weekend. I was very careful with cleaning/oiling, fitted a new mainspring and used a few dots of 8213 on the barrel.
The gear train, balance are as free as they could be - amplitude about 235 deg DU/DD.
Seems about typical for the few Seiko's I have. I know they have low amplitudes, so I'm happy as it is.
I tend to just use my "metric calibrated eye", and of course files/fine grit paper.
You can use one of these, If your eye requires a little more precise calibration.
They do work, but you will still end up finishing by hand/eye with good magnification, and obviously they only work with straight blades, so not much use for drill sharpening or cross headed drivers.