@MA, I do see those die cracks at the lower corners of the Lincoln Memorial. As to the surface discoloration on the rev, it is anyone's guess as to what exactly it is. However, it didn't happen at the mint.
"If you climb a good tree, you get a push." -----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed." -----King Adz