Yup. Was aluminum cable, no one put any oxguard or anything like that on it.
Also, I noticed where the cable entered the house there was this sort of upside down boot over the cable, and the top of the boot was wide open. So it's possible moisture was coming in on the cable and just riding down into the box.
Either way, it was a little scary to look at as the cable on the right had actually started breaking away from the breaker, or that side of the breaker had started breaking off....
Like you said, glad to have a nice new entrance all setup and working!!!