As Nigel says, things can always be made....assuming you have an original pattern to copy from. If the cam is sheared, then something like laser welding can certainly rescue it. If it has been chewed up, then a careful study of the remaining bits may assist the manufacture of a new part. I guess if one has access to machine/mill the bits as required oneself then that's great. To approach an engineer (assuming they'd need to draw up the component as well) to make it could be prohibitively expensive. However, I wouldn't scrap it as you never know...