In my experience only the first and second generation Model Ms really suffer from broken rivets. If it has drainage channels, it probably doesn't have broken rivets!
That is not true at all. Some keyboards I have are pristine and have unbroken rivets, yes. However I can say without a doubt, I have had several with drainage channels that needed a full bolt mod.
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http://imgur.com/a/p6kmH
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http://imgur.com/a/b4Q7Q