Cylinder head damage

The marks themselves will not cause any issues.  Whatever made the marks may cause an issue.  Those divots are from some debris, metal etc bouncing around in there.  Whatever it was may still be in the engine, down in the bottom and may end up ruining the rest of the engine.   If it's "old " debris that was removed at some point, then no worries.  If you want to fix the head, take it to an engine builder or machine shop that can turn it on a lathe and smooth and reshape it.

It may be cheaper to buy a used head off ebay.