Still working on the baffle cuts. The idea is to install the upper cowl and be sure that there is a 3/8 to 1/2" gap between the baffles and the cowl. As everything is hiddent once the cowl is closed, the following trick is used : first put some paper clips on the top of the baffles, then install the upper cowl and then measure te gap from the top of the clip.
As I'm cutting a few 1/16" each time, I needed a few iterations. I still have to make some adjustements.