Here's something to throw a kink into the works...
I have a Contra cartridge where the label was literally ripped off. I picked it up for $5, so it didn't bother me at all as I planned on giving it away as a gift some time here on the site, whether it be a future Secret Santa, contest, or whatever. All that's left on the cartridge are small remnants of a label (T&C Surf Designs, if you'll believe that) that someone tried to tape over what was left of the Contra label.
Would you:
Use a label maker to put a small sticker on it denoting it's Contra?
Replace the missing label with an accurate replacement label?
Replace the entire front of the cartridge from a Contra donor cart (could be expensive)?
Replace the missing label with a fan-art label?
Leave it as-is?
In this case, I would consider it a "player" copy and leave it as is. In this condition though, I think anything other than an accurate replacement label would be considerable, even the option to just Sharpie the name onto it (it's the wrong shell anyway).