Wiring of old house, ideas on why the lights brownout (dim) Could the well pump be the problem or what?

I would put the water pump on it's own circuit. Make sure your breaker box is rated for at least 100amp service. Most major appliances get put on their own circuit. My house was also built in the early 30's had the same problem. Pump kicks on the lights dim for a moment. Put the pump on its own and things got better.