I have talked to Karl about this in the past and his feelings are to re-do the entire part and not try and touch up.
This is one of the biggest reasons I use GunKote over CeraKote - you can touch up GunKote easily.
Plus there is no mixing.
Plus the gloss is not determined by the mix ratio (not easily repeated for a touch up).
Plus it dries to the touch before baking so it is much easier to handle.
I have seen the CeraKote tests claiming superiority over GunKote - I have also seen the exact opposite results showing GunKote superior using a different abrasion method.
I do either for customers and I have GunKote on all my personal weapons.
Talked with both at SHOT show and I will continue to use GunKote unless a customer insists on CeraKote.
Not looking for a pissing match - opinions very - just my 2 cents worth and after doing well over 100 guns. Your mileage may very.
Some guys like Savage and some guys like Remington both work and either will do the job.
Dan
