Revell's 1/72 U-Boat panel lines

If you are refering to the Weld seems on the lower hull then yes they are very correct. This is one of the many finer detail points that Revell put into this kit.
Hope this helps.

Not sure what photos you're checking, but Anatomy of the Ship, vom original zum modell, the U-Boat, etc. all have photos that show these boats with overlapping plates, raised lines...in fact, the whole outer casing sits over the pressure hull. I wouldn't file anything down.