“somebody at CIA figured out that you could very easily hang a couple of Hellfire missiles on the thing and — presto — you had the Predator-B!”
This is a little nit picky, but the Predator B is a completely different aircraft than the Predator A that was first armed. Where the A model can carry two hellfires, the B model is designed to carry up to 16 hellfires, or 2 500 lb JDAM bombs.
No problem... you are absolutely right. The 'B' is a larger airframe with more 'hard points' for weapons stores. (Shouldn't go off the top of my head like that.)