With the flat bit of metal 8.75: long all I can see in the parts manual is a slot like the grass or dirt left on the flat metal where the bolt hole is thus indicating it's possibly from the top of the cutter deck above the discharge port or possibly underneath ,could be used to prevent flexing or cracking of the cutter base where other components (like the chute or guards) attach.
You may need to undo a bolt move the brackets so they are straight then tighten the bolt .
