This is a typical Ingraham kichhen clock movement that came to me with a black coat of dried something all over it.I soaked it in naphtha and ran it in a heated ultrasonic with fresh cleaning solution. It came out looking about like the photos. I washed each in mild detergent with a brush, rinsed, and ran it through the US one more time. It is clean. The dark sections are in the brass. What causes this? Can the brass parts be shined? It came out of a smoker’s house. Could that be it? What do you think?