I just reversed the brass inlets, put a drop of ca in the mounting holes, and reinstalled the servo.

I had a difficult time telling when the screw contacted the brass. I could see when the screw heads touched the rubber but not the brass and I can't understand how anyone would know this, especially when the servo is halfway down inside the plane.

There was no noticeable difference in the torque required to tighten the screw as it went down into the hole, and there was resistance all the way down to the rubber. I guess just going to the top of the rubber is enough, but I'm worried that the screws might be too loose or come loose from vibration. Should I not worry about that?