Went deeper into the cab repairs tonight and began major surgery. The outer rocker didn't look too bad from the outside but the rust was significant inside.
After cutting the rocker spot welds, I peeled it back to find a rocker and front cab support full of dirt and rust. The front cab pillar inside the rocker is pretty much gone too. The inner rocker is in pretty rough shape along with the floor and footwell. I also started cutting out the bad areas in preparation for floors, inner rockers, and outer rockers. I guess I will put a few more patch panels on order.
Here's a few pictures of the carnage.