The rear door lower frame was held on with Tiger seal, filler and luck! We uncovered 3 layers of cheap bitsa pieces of plate behind the corner that then rounds its way to the wheel arch. The welder has broken so for now we've just cut out and gauged the severity in this area.
A new inner arch and lower valance corner have been ordered. We also need to go and pick up some 1mm sheet steel too. This isn't going to be a quick fix as underneath & behind does not match the "finish".