Measured and determined the cowl seam was NOT aligned the way I wanted. Mounted a long piece of .125 angle along the side of the fuselage, and parallel to the cockpit rail. Concluded that the bottom cowl was poorly aligned.
Marked, double checked alignment and measurements and trimmed off a long sliver, tapered slightly from bottom cowl. Will have to repair the resulting gap between top & bottom, by adding material to the top, and re-trimming it.