Whats the best way to model this? (Sheetmetal chute)

The sheetmetal is 16GA.  I opened up an old model from about 10 years ago, the person created a flat pattern of the chute then used bend lines to bend it.  Id rather model it as the formed part if possible, since its easier to get the final dimensions correct.

Whats the best way to model this?  Below is a screenshot of what I tried, create the shape of the part, then shell it out .06, then rip.  As you can see, th corners didnt go so well.SolidworksSheet Metal