Intake (heat shield) and metal gaskets?

I just got back from a local u blast place to clean up some parts one of which was this cast iron intake.
I know some media got in behind the shield, I suppose I could pry one end open and blast the other side with air, but I'd still be worried about some sand/glass that may still be under it. If I grind off those rivets will I be able to refasten it somehow? I think it's only purpose is a heat shield, idk for sure though. Also thinking of using the metal gaskets, the heads were milled just to straighten them up not exactly sure how much though. The machine shop said there shouldn't be an issue. But I figure the thinner metal ones would be a better choice for fitment.

PXL_20240601_013344469.jpg

PXL_20240601_013423041.PORTRAIT.jpg

PXL_20240601_014238856.jpg