After your post I had to look them both up... I think your iden is correct. I do see patches of white in folded wings of both drakes and hens in some pics of Gadwalls, and the hens have a faint two-toned head, but from pics I've looked at the big giveaway is the bill. Gadwalls have a darker bill and Widgeons have a lighter bill with a dark tip in all pics I looked at.American Widgeon. Gadwall has no white, and is overall a pretty bland grey-brown bird.