This is equivelent to the factory Christen left hand discharge vents, part number: 30343-001. This part has already been trimmed as shown in the Eagle manuals. A drawing is shown in the photos, but this is dimensionally equivalent to the factory parts. You should be able to use it as a direct replacement for a damaged factory discharge vent.
Can also be used for other aircraft as well. I can supply a template for the hole cutouts if needed.
To attach to sheetmetal, use the same structural adhesive as suggested in the Christen manuals. The surface finish of this part after when it arrives to your door is similar to that of 400 grit sandpaper. It is also somewhat porous. Finishing requires a few coats of high build primer, sanding inbetween each coat in order to get a surface finish suitable for topcoat.