Rot repairs resumed. The front driver's side corner of the box this time. Bad design from day one.
The passenger side will likely need the same routine.
Luckily I still have enough material left over from earlier rot fixes that I don't have to go out for more bits and pieces.
Plus side is I'm getting better at not slicing through critical areas with the oscillating saw. And better at rot detection. I cut just past the last rusty fastener and that's where the rot usually ends.