This is a cross post but I thought it was kind of a cool old board so I figured I'd post it here too. The switches appear to be most likely SMK J-M0404.
![Kaypro 4 Keyboard, Teensy 175690-1](https://geekhack.org/index.php?PHPSESSID=6otbpn4fj58slpql97kjoqrnd6v392ak&action=dlattach;topic=91047.0;attach=175691;image)
I traced out the matrix with a multimeter, then desoldered the ICs and hooked up the Teensy.
![Kaypro 4 Keyboard, Teensy 175694-3](https://geekhack.org/index.php?PHPSESSID=6otbpn4fj58slpql97kjoqrnd6v392ak&action=dlattach;topic=91047.0;attach=175695;image)
It's short a lot of the keys that are standard now, but I just like the old style boards. The keycaps are nice heavy sphericals and the switches are pretty nice too, if you like linears.