Yeah, you did a good job on the build. It looks much better than the box art!
The kit itself is wrong in so many ways. I had an `81, and just of the bat, I can tell you that the hood/bumper line is completely wrong, the wheels are from a turbo trans am of the era, as you mention it shouldn`t have side marker lights in the rear, the fenders fents are from a 77-79 which you also mention, and everything else is all just generally out of proportion.
It looks like you made the most of it though!