The switches in the VT100 are the subject of ongoing research. There's an Atari forum post which implies that Stackpole and Hi-Tek Corporation switches are very similar, and claims that the keyboard manufacturer is Stackpole (for a photo depicting switches similar to those in the VT100). Hi-Tek went on to produce the "space invader" switch; there's no evidence confirming an acquisition of Hi-Tek Corporation by NMB, although the wording on keyboard labels pretty much confirms it. We don't know for sure whether NMB had any part in the design of the space invader switches.
There are more obvious mysteries. One particular switch has been branded as SMK, NEC, and Maxi-Switch, who were all keyswitch manufacturers in their own right — shared design, or a bizarre rebranding exercise? (The logo is only visible if you desolder and remove the PCB!) GRI sell switches identical to Futaba's old switches, but with GRI branding. I've not been able to get any samples, and no word from GRI as to who actually made them.
In the case of the VT100 etc, did Stackpole simply buy in switches from Hi-Tek for their OEM keyboard production? Did one company copy the other? There's no evidence to prove that either company actually made these switches (Monterey never made the "Monterey" switches, for example; they're SMK). The Oric Atmos keyboard has "Stackpole" on the PCB, but that's not proof of switch manufacturer. There's another keyboard somewhere with "Stackpole" on it.
It's all guesswork. I'm trying to track down anyone at ITW Ark-Les (who may be the old Stackpole switch division) to see if we can find anything out. The old switch division is no longer part of Stackpole. It's a real stretch given the age of this design.
Incidentally, the VT100 switches are actually different to the design used everywhere else.
