In case you didn't discover this, most panels on Monaco coaches where the fuel door is located will open. Some fill doors are mounted in bay doors that swing open and expose the fuel tank, but many are mounted in a panel that is not a bay door and doesn't look like it would open. The non bay door types do open and swing up. You have to look under the bottom edge of the panel and you'll see a single screw, remove it and the panel will lift up. You'll need a broom handle to hold it open. All the Monaco fuel gauges that I adjusted were always on the driver's side.
Here's Centroid's literature. Keep in mind, every time you make an adjustment, you must turn the key off for 30 second and then check.
Centroid
