I think it is metal from the outer rim that has folded over onto the field. Damage doesn't look like that. This is extra metal being where it is not supposed to be. There is an outer taper/bevel on the rim that corresponds to the location of this extra peel. More pics would help, though. 
In Memory of Crazyb0 12-26-1951 to 7-27-2020
In Memory of Tootallious 3-31-1964 to 4-15-2020
In Memory of T-BOP 10-12-1949 to 1-19-2024
In Memory of Tootallious 3-31-1964 to 4-15-2020
In Memory of T-BOP 10-12-1949 to 1-19-2024

























