I recently purchased $100 of Jefferson nickels from from credit union. Naturally the majority were newer nickels from 2011 to 2019. I did find 1 buffalo nickel and some assorted dates in the 40's and 50's. However, there were 2 nickels that stand out. One a 1945-P with a missing "o" in Monticello on the reverse. The 2nd looks like it went thru a war, has a reverse but no obverse. Will attach photos. If anyone has any idea on these, please let me know. Don
the first one is damage the 1945 is a minor grease filled die you can read about it on this website https://www.error-ref.com/struck-through-smooth-viscous-material-grease-oil/
1st Nickel.. Someone very bored and angry decided to grind down the Obverse. That is no kind of Mint Error.. but the others mentioned this already