So I'm visiting my out of state parents and notice my father has an old (judging the appearance, I'd say early 90's) Epson keyboard sitting in the corner of his den. I pick it up, look it over, press a few of the moderately clickey keys, and decide to look under the hood to see what kind of switches are hiding underneath, expecting some kind of ALPS type switch.
The key cap comes off like a Model M's, and underneath is a strangely shaped keystem through which can be seen a silver spring a la an M's buckling spring. Unlike a Model M though, the collar around the spring looked different. Unfortunately I didn't have a camera handy, and I won't be able to inspect it again until I'm back to visit in April, but it has certainly piqued my interest. Was there another non-IBM buckling spring keyboard? Is this some other kind of switch? Anyone care to guess?