It's not that bad, as long as the gun works.
As long as you sand it down rough, then spray some FLAT black onto it, it should look pretty good.
I had to spray a few scraped up gun parts down and it looked great... though, I used regular black at first, and it looked horrible and shiny. After a spray of some flat black metal paint, it was awesome. Painted the markings back on with $1 arcrylic paint and it was good to go.