1. Filled and sanded several areas of the cowl that needed it, concentrating on the front inlet holes.
2. I had previously bonded a thin strip of aluminum to the edge of the oil door opening to serve as a shim to allow the oil door to sit at the correct height. After looking at it, I determined this needed to be beefed up, so I drilled three holes through the strip and the cowl, countersunk the holes, and squeezed three rivets there. That strip isn't going anywhere now.
3. Improved the consistency of the seam around the oil door. Also filled several divots there.