Options to repair or replace driver's side fresh air vent door.

I've fixed a few of those. Drill out the rivets so the door assembly is detached. Weld a little tab to the door or bracket (maybe even both) and then drill them so you can use a small machine screw as the hinge pivot. Clean and paint (or powder coat) and then reinstall the door with pop rivets and washers to the inside. I use hobby foam sheets from walmart for replacement gasket material.