Glad you bought it cause I would have even with knowing what you found wrong with it. I wonder if a HD filter kit would fix all your problems with the filter cover( broken and missing clip). I think it would replace that filter base too. Glad you didnt spend the 600 on a new one. I almost did the same thing but then I got a new 7900 for just a few more bucks than a 6400. Good score man, Im happy for you.