Two Pennies That Are A Bit Odd, Struck Through Grease?

This is the first one. It's the one on the left.
The denticles sort of disappear from the 11 to 4 o'clock direction, and the G in KG look very weak. The leaf tips and the 4 in 1964 are not as raised as normal and it doesn't look like it's from wear.



The denticles fade away. The second photo is of a normal penny and the denticles are clear.



This is the KG. The G is very weak.


I didn't manage to get a photo of the 4, sorry.



This is the second one. The bottom half of the stem is almost gone and also the top half of "NA" in Canada. It looks to have a bit of a strange texture in hand that doesn't show in the photo.



The NA. The odd texture and lighter colour you can see here. I start to suspect acid?


The stem. Ignore the line on the left, it's a scratch.


Are these struck through?

Edit: Added some closer pics from a microscope.