I have built singles engines with similar damage using gaskets with blue hylomar on both sides with success in the past. I have also had cases leak where someone has welded them and they have distorted slightly as a result.
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.