Larry,
those DC/DC charge pumps obviously produce an output voltage that is
higher than the input voltage, or negative. But the output still has a
common ground (0V) with the input voltage. For the panel meters we need
a supply voltage that is within the range of the available voltage (12
to 24V available, 9V needed) (no need for those DC/DC charge pumps),
but that needs to be isolated/free flowing from the main/"primary"
power supply so that we can measure it, i.e. no common 0V/GND. I don't
see how the ICs that you show can do that. On the other side, I wonder
whether there are not really specialized ICs that do that.

Thanks,
Stefan