I have collected the Roman coin, two to go. I have opened the panel in the Chinese room that prompts me to type something in, I'm guessing it has something to do with the scroll I picked up in the Inca room. I have tried several words related to the Chinese template guardian statues: dog, lion, shishi, foo, fu, foo dog, fu dog and a few others but that doesn't seem to be it.
I also have the UV light which I think has something to do with the wall at the back of the Inca room, but I see nothing out of ordinary when I move it around.