My house is 70 years old. It sits partly on a small cripple wall and partly on the foundation wall. There are large beams supporting the center of the house (running approximately every 2' the full length of the house). The house was custom-built and survived the 1933 earthquake (Long Beach, CA). It seems that more cracks are appearing outside in the plaster and inside on the walls and ceilings. Some of the inside cracks look to have been patched before. Is this settling? How do I know? What is the risk of settling? What should/can be done? Thank you.