I'm pro non-grainy finish as well, though a grainy finish would better match my older UGCs. I have a bunch I uncase NES games and I simply cannot bear the thoughts of having to modify more UGCs so I will be keeping an eye on this, Shadowfox.
I'm really curious about the interior of the cases. You say NES games will snap in, but I actually prefer to case my games inside of the black game sleeve as well. Not sure if this will be possible if the games snap in.