Today I marked the location of the upper cowling fasteners that I want to shift to make a better fit. I then gorilla taped the upper cowling into a better position and then drilled out all of the remaining upper and lower cowling Skybolt fastener holes (except the bottom ones that I'll get to later). Once done with the drilling I removed the upper cowling (yet again) and riveted the retainers to the flanges, except the ones in the corners which I need to revert to movable ones to allow for inaccuracies in measurements.