What is an assault weapon? Everybody here knows its a made-up term for a gun with scary looking doodads added. Wizbang has a piece in which they add a visual aid:
To really finish this out, I would have added an elevated handle to mount the scope on, an elevated front sight to compensate for the elevated rear sight, A doohicky on the front to deflect the smoke to the sides, and an adjustable stock and pistol grip assembly on the back.
Someone with a copy of Photoshop could knock this out quickly enough.