I built and installed the entire nosepiece in one morning when I didn't have a camera with me, so I didn't get any pictures of its construction. It went together very quickly. The frame consists of (5) 1/4" x 1" aluminum bars. There are 4 ribs spaced along the width of the nose that each attach to the top and bottom of the OEM bumper and another piece that runs along the midline, intersecting with the forwardmost point of the ribs across the width of the car. Each bar to bar connection is tied by (2) 8-32 screws drilled and tapped into the bar.(holes in upper bar drilled overlarge for screw thread clearance) Likewise for each bar's connection to the OEM bumper. The (5) pieces of sheet metal (0.040" aluminum sheet) were attached to the bars and to the OEM bumper with either 1/4" aluminum pop rivets or 8-32 screws drilled and tapped (where I needed interior access). I used 1/8" rivets for the few sheet metal to sheet metal connections.
The radiator door is a section of 4" diameter PVC pipe with end covers and openings cut into it so that the openings become exposed as the pipe rotates. Think of it as a cylinder with two 45 degree full length slots cut on opposite sides that rotates 90 degrees to either expose the solid side or a slot of the cylinder to the opening cut in the sheet metal. An actuator cable attached to the outside edge of the cylinder causes it to rotate.
Here's a pic of the early nosepiece when it was still covered with unpainted coroplast so you can see the lines of screwheads that follow each of the 4 ribs and the crosspiece that runs along the front. When I later replaced the coroplast with sheet metal I copied the patterns of the 5 coroplast pieces I used to cover the nose.
Here's pics of the sheet metal/ pop rvieted nosepiece with the radiator inlet in the opened and closed positions.
