71 Dart 410 stroker ..

In my opinion it don't look that bad. Yes welding it back up and smoothed back to pe accident would be the best way.
It's hard to tell with just a picture but i think you could clean that head up with some sandpaper rolls............ yes you will have a little less compression in that cyl.............clean it up, cc it, and then decide if it's time for professional help. I know this is not something that you do..........but what is it going to cost you........a hand full of sand paper rolls. If they weld it up......you will need new intake and exh seat as well. might be as cheap to buy a new casting and put you stuff in it. Just kind a thinking out loud here.