![[Datsun 1200 encyclopedia]](/wiki/upload/wiki.png)
Yes, you should turn the flywheel if it is not in good shape!!! Better to not re-grind the flywheel if it doesn't need it.
It is not indicated to resurface the flywheel UNLESS cracks appear, or it is not flat (worn unevenly), or the surface is burnt (heavy glazing). Guys will tell you "it is cheap insurance" to machine the flywheel regardless, but that's not what the Datsun factory service manual says.
If it is warped, have it resurfaced. It is it burnt, chattered, or is grooved, resurfacing is called for. But it if still worked great, is flat, and not burnt, don't bother. The Nissan factory service manual does not recommend a resurface unless needed. Every time my Datsun flywheel did not look great, I should have resurfaced it. And everytime it looked great and I didn't resurface it, all was fine.