Cutting the actual hole took about 2 minutes or so. I put very little pressure on the drill as it is cutting. Keeps the saw from grabbing and tearing the aluminum.

Cutting the big guy. This went just as easy as the two smaller holes.

All of the holes are cut and deburred and test fitting the gauges finds a couple of issues...
In this pic you can see how the gauge cover fits nice and tight to the aluminum.