Yeah, exactly. I'm also going back and forth on back plate material. Right now I'm using a kind of inexpensive zincy brass. The kind that's pretty brown when rough and silvery with a hint of straw yellow when polished. Not too different from what was used In the original m7's and early to mid K47s. Copper is expensive! Plus, it's not even accurate to use a "nicer" brass. If I wanted to be strictly accurate I would use this for the K47 and a more yellow brass for the k87 but that sounds like a waste of money for no difference in performance.One must wonder what sort of thermal cycling (?) (which wouldn't melt the diaphragms) would cause the screws to even get close to starting backing out.