It really sucks when you find that effect on a decent date. I recently found a 1909 VDB that had scale corrosion like that. The seller had it for a while and it was getting worse. I had suggested that he conserve it before it got worse. 3 years later, I bought the coin cheap in hopes to conserve it. I soaked it in distilled water, acetone, then Verdicare. One more soak in acetone to remove anything that would lift...then a light coat of Verdicare again. Better...but not great. An XF details coin at this point, but at least the 'suffering' was ended.
The flat-shelflike 'separation' is machine damage. A tiny wobble in the tool/press during the strike leaves a smear on the devices. Outer devices are mostly affected, but interior devices can be affected to, like the profile or a mintmark. You'll see on Lincoln cents in the 80s especially with small MD occurring on the earlobe.
I certainly see what you’re talking about. Just came across this guy, and a 1955 wheat. this one is impressive.