With that keyboard being made in 1994, the likelihood of the it being a rubber dome is high. I couldn't find anything specifically about that board offhand, but the MicroSpeed KB105M is mentioned in a few places. Here is one:
Looking for info on a certain model of keyboardApparently it was marketed as an affordable alternative to Apple's own keyboards. Interestingly,
this article says that people who tried the KB105M ranked it just behind the Apple Extended keyboard, and ahead of the Extended II. Both of those boards were likely to have Alps switches, so maybe there was a version with mechanical switches? Maybe it was placebo effect? Maybe some people actually preferred rubber domes?
None of that directly addresses the KB106MD, but it might give you an idea of the goals of the company. Maybe somebody has actually seen/had one.