Check out the nintendoage ezines for a beginners guide to sealed stuff:
http://nintendoage.com/in...cfm?FuseAction=eZine.HomeVolume 1 issue 4 and Volume 2 Issue 1 in particular. Both written by Bronty who at one point was 3 NES games shy of having a full sealed collection both licensed and unlicensed. I dont think there is a more legitimate source of information on sealed NES than him. Of like Duke said post some pics on the nintendoage forum and there are about half a dozen hardcore guys over there that usually help out with sealed stuff fairly quickly.
Did Bronty ever finish his collection?
The sealed N64 games I own tend to have sub-Nintendo quality seals, likely because they are crappy, late-release games (Razor: Freestyle Scooter, PowerPuff Girls: Chemical X-Traction, etc.). I would imagine Ogre Battle would have been a nicer seal, but I agree with Duke and Crabby to go check out NintendoAge.