I think you will need to consider that any Airstream repairs will have to be done by a good Airstream service facility. We had 14'x4' streetside aluminum replaced recently. My search revealed that SOB (Some Other Brand) service centers will not and are not able to repair Airstreams. Most panel damage has to be replaced as aluminum will not 'pound/pull out'. Aluminum stretches and will not return to it's orginal shape. Pre-shaped ends and corners are available.
Neil and Lynn Holman
Kirk Creek, Big Sur, Ca. coast.
1966 Trade Wind
1971 Buick Centurion convertible
1969 Oldsmobile Ninety Eight