Looks like that wire was hot and shorted on the sharp edge below it. I changed my mind about bolting them together. Cut the red ring terminal off behind the short, and solder or crimp a new ring on, then bolt them together.
I agree. If the conductor is damaged then bolting them together doesn't solve that probem.
Can't tell from the photos whether the ring terminal and the wire lead can be cleaned up and then spliced in. Should keep that option open if a new ammeter is in the future.
Regardless I would not just bypass the ammeter and assume that and the damaged feed wire are the only issues.