Here is a shot after the repairs – we have welded in a patch to the rear bulkhead with 18-gauge cold-rolled steel, and also added back in the lower 1/2″ wide flange, which was messy and cut off during dissection. Once we have the subframe in this car, that flange will be irrelevant to the structure, but we need it to align the floors, and it will also seal things shut tightly.