Installed flanges on right side. Determined best postion of cowls in order to drill holes for fasteners. Decided to mark and drill the holes with the cowls off. Marked the lines of best fit and duck taped the upper and lower cowls together and removed them as a unit. While resting on the garage floor made sure everything was aligned and taped and clamped everything in postion. Marked the holes on both sides of the cowl and drilled. Riveted on the receptacles and reinstalled the cowls on the plane. Put in all of the fasteners and it is surprisingly well fitting! Need to sand the upper cowl where it meets the lower cowl to match everything up even better.