In my experience it is a shield between the exhaust crossover portion of the intake on the lower side. This portion of the intake is very hot and part of the cold start sequence to keep the carb from icing. A condition unknown to our "southern" members, who for the most part are not very up on a "choke" either.
the shield keeps the oil from the lifer gallery from "baking" onto the bottom of the intake. These shilds can get filled up with crap-o-la and a thorough rebuild has them removed, cleaned, and reinstalled.
No problem with a weld fix or a dent here and there.
Rob