While I understand that the damage is cosmetic - as a past buyer and seller of Nordost cables I have found, and would expect, that any damage to the look and layout of the conductors is simply unacceptable -- there's plenty of other cables available without these issues.
As others have suggested your best bet is to split the longer length and sell this as a 7' pair with the other piece thrown in for free -- frankly I think you'd get as good as if not a better price then you're currently aiming for with this combo.