I would think that lower part could be bent back up. But I'd suggest removing the metal from the stock so as not to do any damage to the wood or portions of metal that connect to the stock. Frankly, I'd take it to a gunsmith who has the tools, vice, etc , that is necessary to do the re-bending. If that gunsmith doesnt sound competent/capable, take it somewhere else. Thats way too nice a gun to let it get buggered up.
Make sure they don't heat it as it will discolor the metal. After you get that done, go to the CMPicon forum and ask who replaces leather....theres a guy on there that supposedly refinishes them and does a good job on leather. I just don't remember his name or email addee. Thinking about this guy, I suggest you find him, contact him and I'd bet you he would be the just right person to do the bending since he's worked on a lot of M1A1icon's.