Very good repair job! I do that, too, using the aluminum sheet. In my case it has always been the lower skirt part of the grille that is broken, where the area around the hinge is attached to the pivot attachment rod, is located. In particular, the hinge point is usually broken out, so I add a piece of aluminum wrapped around the pivot rod and bolted through the plastic with a bolt and nut which is behind the pivot rod.
Here is a link to the thread about how I fixed the plastic skirt of the hood grille.
http://www.mytractorforum.com/showthread.php?t=127192
Here is a link to the thread about how I fixed the plastic skirt of the hood grille.
http://www.mytractorforum.com/showthread.php?t=127192