I'm about to tackle a rusty area on the bottom of one of my rear half doors. My idea is to drill out the spot welds bonding the skin and the inner doubler at the bottom edge and cut out the rust below the radius between the corners. Fab an insert and weld. There is also rust between the skin and top edge of the lower part of the doubler. Should I go further and remove the whole doubler on the lower part of the door, treat the rust, patch and weld back in place? Or is that overkill?