You realized that missing portion melted/burned away. Had that happen to a 43 that massively overheated. That smeared metal on the rings is melted aluminum.
Odds are very good more than just that piston has issues. I would put a smogger 400 in place of that 383 before I tried to cheaply fix it and only if I absolutely had to have it running to get rid of it.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
