even if they looked good, there will be pad material transferred to the rotor, and the previous material may be playing havoc with the material of the new pads, thus brake performance will suffer.
the 80 grit on a da would be a good first step.
you have nothing to loose by trying that.
just don't dig any divots in the surfaces doing that.
80 grit can cut faster than one thinks, and iron rotors aren't that tough to start with, material removal wise.