Well if I remember correctly, I was doing to lowbies quest there one night, and found 3 of the 4 pieces in like 5 min. So I would guess the 4th one would be there too.
Mmmm I think there are only 3 coins could be wrong on that and yes the coins are in BB but he asked where to turn them in. The turn in person is in NQ just as you zone in from main land go to the little park like deal that will be in front of you. She is there under a tree. BTW you turn in all collections to her.