I am restoring a 1982 SL280, the cowl panel in front of the windscreen is badly corroded, removing the two grilles, one on the O/S and one on the N/S revealed further rust under the cowl, this panel below it is the one the heater blower mounts to, it is welded to the bulkhead. I want to replace this panel along with the cowl panel, unfortunately my local dealer cannot locate this part, the cowl panel is no problem, its the panel below it, has anyone replaced one of these panels? does anyone know the part number?