Some nutplate work here. There are six screws joining the top and bottom cowls at the front. See Picture 1 and 2. The screws have nylon washers, very easy to lose. Too easy, in fact. I had to order more from Vans.
There's also a nutplate for a screw to attach the metal tab (Picture 1) at the front of the horizontal piano hinge. This prevents it vibrating out. Tim, my inspector, was pleased to see this. He was less pleased to see there is no safety mechanism to prevent four other hinge pins from escaping.
Picture 3 shows screws in nutplates at the bottom of the cowl where it attaches to the forward fuselage. All told there are 8 piano hinges and umpteen screws holding the cowling halves together and to the fuselage. Compared to the arrangement on my Robin 2160, this is a "really" secure/rigid cowling.
