Deburred and clecoed firewall component of hinge, Then riveted, successively to avoid working the 'bulge' of the skin in the process. Bottom TWO rivets cannot be squeezed ... mount too close.
Then repeated all of that for bottom hinge. Probably needed a spacer to increase clearance for the thickness of the filberglass in the cowl bottom layer. There will be a slight 'step' in the AL & fiberglass surfaces. Too late to drill out for the minor issue.
