I'm gonna go with your first hunch, the NEC ... especially since it mentions lithium protection / notebook power in the applications - that's exactly the circuit I extract it from
I did find that fairchild part searching those numbers on digikey, I guess the chip could be either, the ratings are fairly close... it could be neither as well, only one way to find out!
If you can't find rateings you can always just set up a thermosistor coupled directly to the fet set at a typical over heating temperature and gradually increase the amperage through it till it starts overheating.
If you can't find rateings you can always just set up a thermosistor coupled directly to the fet set at a typical over heating temperature and gradually increase the amperage through it till it starts overheating.