Wow! I wonder if the transmission mount had been loosened at some point and had the bolts re-used? Seems very strange that the bolts would be that beat up unless they were loose or re-used when they should have been replaced
That's what my thoughts were too. I've been the only owner, but I don't remember ever having had the mounts replaced. There's a chance someone undid them to do some other work and re-used the same bolts, I guess. I'd hope it wouldn't get that bad on its own.