I have been working on a few things, but have gotten the correct fill and fiberglass strips installed on the bottom cowl. I'm pretty pleased with this really. After taking the halves apart, you can really see how much bend there is in the top cowl, and why the aluminum mounting strips would be less efficient here. Thanks to Dan H for that.
For the fill, I first sanded a scarf joint and about an inch down along the seam. I assembled the cowl in the garage and used tape (LOTS of tape!) as a release agent and mold. I taped over the edge on the top half and allowed for about 2" of overlap. Then I put a piece of tape down the seem and filled it from the back with thick flox. I squeegeed that and let it set. Then I separated the halves and sanded the back of the flox.
I then re-assembled the halves and followed Dan H's method to lay-up the mating strip. 5 plies of 2" 8oz tape. Worked like a charm. I did one on Saturday and the other Sunday. On the right hand side, all five plies run the entire length. On the left side, two plies run the full length of the seam but there is a gap in the other three plies right where the forward edge of the #2 cylinder is (you can see this in the pic.) After measuring the thickness, this was probably unnecessary, but should be ok nevertheless.
Test fit tomorrow!