I assume that could bent back too if it was bent into that shape and not ground.
Never done it before, but could probably do it with zip ties and a big pair of pliers.
Put a rag around the dropout put the pliers on the dropout and then tie the zip ties (or rope or whatever) through the rear triangle and the pliers so it prevents them from slipping off. Then gently squeeze the hell out of them and make side to side corrections in a vice and alignment tools (those popsicle cone things) afterwards if needed.
However, if some fool ground away material to accomodate some obscure axle then bending won't work.