During my Xmas break, I went to Panama to see the family, and strolling through the hardware store, I noticed they had small aluminum sheets. I got a piece of stock .064 X 4 X 10 inch and made the missing piece (I was THIS far from taking some of the carbon fiber I had laying around for the multirotors, but this saved me from having to do that!).
Here's the piece already made. Notice I srubbed the borders, so that the silicone will have a better surface to adhere to.
Here's the airbox all cleaned up (it was not really that dirty to begin with)
Test fitting
Now, I have some black LocTite brand silicone, but whatdo you guys think? Just the silicone, or use rivets as well? I only got regular rivets, so I am leaning more towards the silicone alone... But I guess if its not going to be enough, better to do it right, as I don't have any more aluminum to make another one!