Dust and dirt on inner plastic well? 0

[UncleAnwar]

Never seen this before, just bought a 2.0 ff4 and there looks to be dust/dirt smudges on the inner well by the spine?  Should I be concerned with tampering?

[joeypost]

Are all the edges sealed properly?

I imagine it is debris from the book falling off and getting stuck to the plastic. As long as the edges are sealed properly, you should be good. 

[KCOComics]

It does look related to the book based on the picture. 

[UncleAnwar]

Looks to be sealed ok from what I can tell.  Guess I won't worry about it then.