The lower banana wrap dent isn't too bad in the first place. It could be gently hammered to a more regular contour if you end up disassembling. I did that on my Argosy and the result is quite good. I suspect rivet holes may need to be re-done. The belly skin may be corroded thin anyway, but doing a small belly skin patch will be out of sight if necessary.
The roadside rear corner is more severe. I've seen repair manuals for some years that have diagram of each component and panel number. Availability? If available it is very expensive -- any Airstream dealer could get that info for you. Might be tough for a DIY-er. Even worse is that this is a major disassembly and requires a fairly high level of experience -- but I think many would be able to manage this if they're handy in the first place. Aluminum stretches when it gets dented, so hammering this out is not an option.
A novel but workable approach is bondo bodywork and repainting the whole trailer. Can't lay my fingers on it but there have been some member photos -- a silver/aluminum painted Airstream is darned hard to distinguish from the original. I have seen member BigAl
's Airstream that was painted due to some metal issues. He doesn't maintain anything in the photo section here but it looks good.