Regardin aluminium alloy break - I toyed with this idea but abandoned it for I think not galvanic action but errosion. I am not sure but I think hot jet of expanding gases will eventually errode brake vanes or ports. Is there a market for break with dovetail? Don't think so. Too many options available already, there is no problem shipping across the border, cheaper and effective breaks. And - most gunsmiths probably make their own breaks for its not much more than threaded pipe with holes in it. And - all M14s end up being scoped eventually.