Hi jeri,
As Doc PAul said, there's usually a small detail that was missed:
Be sure that you've checked Moira's office completely.
Be sure that you've checked curator's office completely.
Be sure that you've checked red curtain room completely.
Be sure that you've checked the 2 statues on display cases at top level hall and zoomed close at both of them.
Be sure that you go down the front stairs.
MaG