I have a pair of Model M keyboards whose trackpoints are dead. I also have a stash of old mostly-dead Thinkpads, the ones with the removable keyboards. Years ago I had run across someone's unholy transplant of a Thinkpad trackpoint into a keyboard, but no amount of googling has uncovered it.
Does anyone have any relevant information, such as, what are the seven traces that the Model M's trackpoint puts out, whether they correspond to any of the traces from the thinkpad TP, and so on? I can always use a microcontroller to convert whatever they are putting out into ps/2 signals, and then feed those to the the output of the keyboard -- I know how to do the software part, it's finding the right hardware that eludes me.
I know about Unicomp, but their trackpoints use switch contacts, not strain gauges, and the feel is completely different. I used to have one, I could never get used to it. It's a pity, because they are the only manufacturer of buckling-spring keyboards. I did get in touch with them recently, and they claim that their customers like the switch-based trackpoints better. I don't believe it, but there was no point in arguing.