Brad~
Nice job! Very good first bird - it will certainly lure the wild ones in front of your gun.
Here are a couple of thoughts:
1) I appreciate that you have toned down the sides. I see many birds too "yellow" in this area. Because of the vermiculation on each feather, the sides show as an olive to my eye. I typically mix Yellow Ochre with Mars Black to paint my sides.
2) The bird looks tall - which is not a problem if the body is wide enough. I like to exaggerate the width of the body on my gunning decoys so they will ride well in a wind or sea (neither of which, of course, is found in allot of Woodie habitats....)
3) You've got the lights and darks about right. This is the most important aspect pf painting gunners. White areas are especially important - I believe ducks use them as a key feature in species ID. Two things I would look at on your bird: the white spots/stripes on the chest are wider low on the chest and almost disappear at the top. The black&white edges of the sides feather arte in a single row - you have a second row lower down.
Here is an Allen gunner I painted about 20 years ago:
Here is a detail from a mantelpiece Woodie from a couple of years ago. I offer it to show the white on the primaries and the trailing edge of the square tertial feathers. On gunners, I would be sure to show these areas of white - but simplify them. No need to paint each primary. You can join these 2 white patches (tertial edges and the primaries) into a single white shape.
Hope this helps!
SJS