Countersunk both end tips and dimpled end skin. It took a while to get a consistent countersink on the tips, partly due to being overly careful with the material type and also because the microstop tool edge overlaps on the lip of the fiberglass when countersinking. Attached control horn to trim tab skin and test fit hinge. Spent some time deburring left skin that had some rough areas on the surface around the pre-punched holes.