I measured and drilled the perimeter rivet holes, then machined a plug for the receptacle and used that to define centre while I drilled the fuselage. When that was done, I drilled out the centre and installed a blind rivnut so that I can remove the plug for charging/power. Later I'll dimple the rivet holes, prime the carbon fibre and inner skin (to prevent corrosion between the carbon and ally parts) and flush rivet the fitting in place. I'll paint over with the plug in place, then pull the plug and let the paint surface tension smooth itself around the hole.
