I put a small screwdriver in my flight bag so when my captain insisted on flying with one wing up with the ball centered on the 737 200 when we were level on the ramp I used the screwdriver to put his ball in the middle and it worked every time. The inclinometer in the 737 200 had a screw on each side to level it. He was always out of the cockpit of course when I did it. I just wanted our airplane to fly level as it should be flown.