Take a good look at your SteelBooks when you get them, looks like the "Clamp" mark is back.
It's not as pronounced, at least from what I can tell without opening them, but there's definitely something there.
One copy even has a slight bend on the front cover opposite the clamp mark.
IMO this suggests that it's due to the warehouse picker simply pulling forward on the SteelBooks from their storage racks, instead of lifting them up and out.



The inside circle is an actual dent, I tried to get a shot of it, unfortunately with the reflection, it's pretty hard to get a good view, again it's not a major dent, but they all seem to have it, and that's not right.