Hey, I'm new to this forum, but lurking here and elsewhere led me to buying the Filco with browns that I'm typing this on, so thanks for all the info. That's not why I'm posting though.
Since I recently learned about mechanical keyboards, I went back through my junk heap and found something interesting. It turns out that the Amtelco KB163 keyboard, a call center keyboard I got from a garbage bin at work, is actually built out of Cherry MX blacks! I had dismissed it as rubbish because the linear key action felt mushy to me, having been used to rubber domes and a model M before that. I guess I just hate Cherry blacks.

Anyway, this thing has 60 function keys and comes in both PS/2 and USB. It's sold with the Amtelco call center package, so you can't get it new, but used ones pop up on ebay, including
one for $65 available now. I
worked out how to map the function keys in AutoHotKey, so if you want a giant keyboard with 160+ Cherry MX black keys, this is something to look at. Oh, one weird thing: some of them have weird numpads: inverted (phone pad style) numbers or an extra star key where the period should be.
(Incidentally, since I have this, the Filco, and a Razer I ordered for work, I think I accidentally just became a mechanical keyboard collector.)