The missing place entry is Hell, obviously, though I cannot personally confirm myself yet.
Entry 41 on monsters is the Alien Queen, that is a fact.
The mastermind of the alien invasion. She has incredible psychic powers.
48 may or may not be Anubis II (uncomfirmed)
as far as items, the necronomicon is most likely entry 32? again, cannot confirm.
and concerning traps, i'm still wondering about entry 13 myself! has anyone been squished by the drawbridge in the haunted castle? perhaps that could be it