Hi Debi
Probably the question that first needs to be answered, is whether Gamel actually existed, or whether he is part of a fanciful genealogy. The current source on his profile doesn't look particularly reliable.
If he is just a product of a fanciful genealogy, then what his LNAB is, or should be, probably doesn't matter much. If he did exist, then finding reliable sources to confirm this might give other clues as to what his LNAB should be.