How to verify a true legitimate factory sealed atari 2600 game?

Hello Guys, Not sure if this is the right place to post as Im new to the forums and am thinking of starting a small set of VGA graded atari 2600 games. I was wondering how to tell if a sealed atari 2600 game is a legitimate factory seal and not a re-seal? What things/signs to look for when spotting a re-seal. For instance, like how NES games come with an authentic H-seam/factory vent holes. I would like to get some info/help from the community if possible. This would be great to hear some replies. Thanks.