Scatter shield vs bellhousing

When I brought my '70 Ruster beater, /6-three tree, bench seat, vinyl pad floor, I notice it has a hole in the passenger side hump. I figured the PO had something mounted there at one point and didn't fill it back in. One day driving over some rough train tracks something falls onto the passenger side floor. I pick this thing up and it's cast, curved, about three inches long, but clearly broken on both ends. Thinking WITF?
Finally dawns on me it's part of a pressure plate.