My Pearson 323 came with an old autopilot that isn't working properly. It holds a course under power but not under sail. I opened the unit and there is air in the compass about 1-2". Benmar wants about $400 for a repair. Since there seems little to lose I was thinking of drilling a small hole and filling the compass with mineral spirits. Since the unit is old I am worried about spending too much money on a repair. If I am spending money the new GPS controlled units seem attractive.Comments or suggestions??Anyone with a working control unit/whole system for sale??ThanksTom