Once you put the paintings in the right places (just move them clockwise to the right wings), you need to take the Forgery Detection training. Once you pass that, you get the key to the Supply Room and you can get the last Dragon Face picture piece.
after you get a job at the museum
Put the pictures in the right category.
go to the guy near the door. talk to him.
You have to get a job at the museum after you take the underground tour
you get them when you get a job there. Talk to the assistant curator
You have to re do it. It is not that bad.
Counterfeit IslandNo, Counterfeit Island is real. In fact, it'd be better named as "Art Island".
talk to the BLACK guy in front of the coffee shop
there is no mansion on counterfeit island
You do not die on Counterfeit Island.
veus jent jyent lone lune bline
the answer is permanently unknown. thanks i hope i helped all of you unsure people out there