Wow! This is worse than what I did on my 2nd mod and I did pretty bad then. This is a case of too much power tools. It looks like a grinder was used to cut the side panels. Problem with cutting such a large side panel is that you do not have much strength left in the panel itself, so if the saw or wheel catches during the cutting process, the whole panel will go bendy.

If Ianho can salvage this case, then my hat off you. Some of the stuff look repairable, but the side panels looks really terminal. It might be easier just to build new panels!