Im confused, are you redistilling GNS, or are you making gin from gns and looking for the heads cut for the gin run? If the latter, I normally conduct a demisting test -- dilute the distillate to bottle proof, if it's doesn't cloud you're good to go. Taking a "heads" cut to eliminate the possibility of bottle-louching is different than taking a heads cut when redistilling purchased GNS (or everclear, etc)