Spent the whole day trying to fit the top cowl. The main issue reside in the 2 front top corner where the cowling sits proud of the F-671 skin. I came to the conclusion that I will add shims between the firewall flange and the hinge which will lower the cowling. First test looks perfect.
I am unsure how differently could have I done things to get it right the first time. It's frustrating as I wasted a whole day in trying to come up with a solution.