How would one differentiate severe/deep toning from a very similar looking dark tarnish which allegedly would have a stronger effect on a high-end proof grade if I understand it correctly?
Secondly, if toning is mild enough (without corrosion), are there documented cases of some proof coins having still received an MS 70 designation?
Secondly, if toning is mild enough (without corrosion), are there documented cases of some proof coins having still received an MS 70 designation?



















