The Worst Mouse Damage Ever and the guy has not even looked under the Plenum. In this case I would be scared to look under the Plenum.
There are a lot of items the mice have chewed on that will prolly still function perfectly but look bad. I have never seen so many different items the mice have chewed on (and the Plenum has yet to be removed) as this case.
Just a Warning.....it can get BAD 
The Worst Mouse Damage TIPS