I decided to rebuild my current 3-lever switch rather than get a new one, and since I couldn't find much about it online, wrote a quick writeup on it:
http://pages.suddenlink.net/randygar/switch/switch.html
I'm not sure how useful it is, but even if someone just wants to see what's inside of one, hopefully it helps somebody somewhere. It probably counts as a draft at this point, given I haven't even spellchecked it yet...
Mine was pretty clearly not a good candidate for a rebuild, but it works now, so that's something!
--Randy