Hi Dave, interesting to see inside one of these, I have seen ones where the switch contacts are actuated by a motor before, but not one with solenoids like this. It looks like some effort has been taken to prevent the mains and grid terminals ever being bridged, in order to guard against backfeeding.
One thing that wasn't clear from the video is what would happen if the mechanism jams, either due to an internal fault, or by the actuator being held externally. Will the microswitch still shut off the relevant solenoid? I very much doubt they are rated for continuous duty, I can see the magic smoke escaping (or worse) if they are left energised. Hopefully there are some thermal fuses at least?
I think those metal bars you saw are for arc quenching.