Looks like someone dropped a socket and it got lodged.... or could have been a rock or something.
Your mounts are probably fine. Belt...no so much. Wow only 8K.
A buddies bike. This one was a 3/8s that was in there for a few years:
wow way worse than what mine looks like. Did bike have any weird vibrations with the socket in there? I posted on another forum got a response looks like a bolt was in there and eventually fell out.