Did the famicom games come shrink wrapped originally? If so how often do unopened copies of games show up?
No they didn't. Disk System games have a little Disk-Kun seal, but I don't think there was an actual way to tell if a Famicom game was opened or not.
Of course, there is - if the flaps are both stiff you can straight away tell if it's been opened pretty much. Of course, you can only tell that when you open them, so it defeats the idea ;)
to me, the whole sealed thing is silly as you're never sure what's in there unless it's a red nintendo seal. Even the 'horizontal' seal on NES games can be reproduced pretty easy.