if you have the keyboard on hand, then try to pull a keycap (very straight, else if it is a mechanical you may break the stem) or try to type on it, if it feels good who cares what it is

although if it is tactile, actuate at the end of travel and has a quite rubbery feel on bottom out then it is most likely rubber domes. although no shame in that

apart from the Zenith keyboards though i never heard of a bull group keyboard that was mechanical so do not get your hopes up though.