The top right looks like it could be a
Dell QuietKey. There exist several models that look almost the same, of which early models are considered to be one of the better rubber dome keyboards.
The two at the front (1,2) and the one on the right above them (3) look like keyboards from BTC. Switches should be
rubber domes with sliders. All keycaps that are not stabilised should be compatible with Cherry MX. I am more confident of (3) than the others..
However, the keycaps are quite yellowed, are of ABS and probably have laser-etched legends but the profile and texture should be very close to Signature Plastics' DCS profile and compatible with O-rings. I have BTC keycaps on my ErgoDox.