I was going through (2) brand new box last year in December. I found 4 of these pennies, one right after another. Plus, on another note, I used a microscope and keep about three rolls worth of MS68+'s from both boxes. I will leave those for my daughter with instructions not to sell until she's 60.
Flat and shelf like is machine doubling. Hard to tell from your pictures, but it seems like there's actually too much there for it to be a doubled die. As far as I know from reading https://doubleddie.com/58201.html and what DD I have seen and come across from newer coinage, you're going to only see very small DD like little bumps here and there -- never full on doubling like you show.