Ummm…. Rust? Mold? Tarnish? Verdigris? It sounds to me like this harp has been stored someplace very damp. If it’s been wet enough to rust the pins and form some kind of corrosion on the discs, you should probably take it to a harp technician before you do anything else. That kind of dampness can also warp wooden parts and loosen glue joints. Plus, after ten years, it’s going to want complete restringing, new felts, and a regulation.
Keep us posted!