Very nice work Blackbird!
Did you bend the u-channel, or weld it?
I don't see any welds, so I would be very impressed by your attention to detail if you did weld it. If not, I am very interested in your technique with bending it, as I am considering an underbody tray for my car, and aluminum i much lighter than the mild steel I have lying around.
Either way, it is really clean! I like it!