So, apparently they have trouble finding Mint Condition N64 Cartridges.
I figured, why not crowdsource these as well?
I just went through my stack of loose N64 games and fount 7 Cartridges that are in mint condition and I wouldn't mind separating with, because they are either bad games (such as sport games) or duplicates (I have 3 DK64 cartridges). The front stickers are scratched on some of them, but they get replaced anyway and the back stickers are perfect as well as the cartridge as a whole.
I also found one cartridge that is is mint condition, but I was stupid enough to put a non-removable sticker on top of the back sticker, so if they need perfect back stickers, it would not work. (except if they used it for mine, since it has my name on it XD)