Be very sure before you put more bend to that buttplate, that this is what you want to do. A curved buttplate usually has to be mounted at the top of your bi-cep of your arm, while a flatter buttplate can still be mounted in the pocket of your shoulder. If you mount a rifle out on your arm, the LOP needs to be longer, than if its mounted to your shoulder, closer to your neck. Either style buttplate works, but has its limitations as well as merits.
Oh, obviously, you can put a shotgun style, flatter buttplate out on your arm, if you want to, but a crescent shaped buttplate usually hurts like the dickens if you mount it to your shoulder.If you are looking to have a copy of a named style of rifle, then you probably will want to use the same style buttplate as the original has on it.