Family '64 4-door Valiant winter re-do

Found I had more rust than I thought on the right side behind the wheelwell. Looks like I'll need a patch panel. At first I thought I could fabricate a small patch and fix it, but it's rotten all the way back. The other side appears to be perfect, even with some serious jabs with a pick. The car spent many years parked against the curb at my grandma's house and I guess that's why this side got so rusty.