Made from the top of a drier. Cut with an angle grinder and tacked together. The indented portion of the large piece overlaps the small piece to make a sort of boxed reinforcement slash alignment jig. Plus, I figured that it would make wiping sludge out a bit easier.
I folded the "foot" (part that rests on the sides), but forgot to take a photo of it. Imagine a flawless rolled edge. Now imagine a mediocre one. Go a few more steps in that direction and you've got it.
All the perfumes from decades of laundry are released when you heat a used drier. Bonus.