I have just acquired a Poole clock which takes 3 1.5V D batteries. However, the contacts come down every 4 seconds or so to keep the pendulum moving instead of every 30 seconds on my other Poole. What could be causing this, and what would be the best way to remedy it? Also, it is dirty with rust in various places. Can the movement or part of the movement be cleaned? I know that oil is not allowed. Any suggestions would be much appreciated. Thanks to all.