Ok here goes: Use the 3 proofs in the MTF model room to open a new area. Go down the ladder & past some spiders 'till you get to another ladder. Go down it & you should be at the Albinoid Pool room. Your Eagle Plate is in that room. Combine the 2 Clement chemicals to make a mixture. After you leave this room, use the mixture on something in your inventory.
(I didn't want to give it all away, so I left out a few details. Hope you don't mind.)