Both appear to be environmental damage. The 65 looks like it was buried for some time then rediscovered. No telling what caused the 80 to discolor that way, something as simple as the tiny particles of moisture in your breath can lead to carbon spots on coins (Breathe through your nose while examining coins, they probably wont show this during your lifetime, but there will be collectors in the future who will appreciate it.) I don't see any clad missing from the 80. Kirk