Completed riveting hinges to cowl. Attached upper and lower cowl to fuselage, checking fit. Will need to sand to achieve 1/32-1/16" gap between top and bottom cowl pieces. Back drilled lower cowl closeout, installed nut plates, and attached to the lower cowl. Next moved on to "Step 1: Remove material from the upper cowl louvers to open the cooling slots as shown in the detail view of Figure 1." I've been dreading this since day one. Not enough room to get a Dremel cutting wheel (at least not me) and control the cut. Decided I'd do it the old fashioned way... Drew a center line on each opening. Drilled with #30 drill, and connected the holes. Once done I was able to get my PermaGrit flat sanding bar into the slot and sand away. Corners and ends also done by hand with a variety of files/sanding tools. Lastly, did my best to match left and right sides, as well as keeping up a consistent look across all slots. Final step for today, added the oil door.

I'm sure there's an easier way.