UNICOMP bought the patents from IBM and still cranks them out from a little factory in Kentucky. They sell the classic Model M, variants, and also a monster 122-key thing. An extra 20 custom keys might be nice. http://pckeyboard.com/page/category/PC122
I have a Model M13 (M + Trackpoint) I bought from a thrift store as a teenager and cleaned up, but right now I'm on a Das Keyboard Ultimate S, which is much quieter and easier on my roommates. I still prefer the actual M feel, though.
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