The comments are well done and I am impressed. I would add the maker of the new one, partly as a tribute to them as well as gathering feedback from others.
The fact that one compressors runs 24/7 might indicate it has failed to on 24/7 - also the ice block also says this? Thus a replacement thermostat might well reduce the KwHr used by the 24/7 operation. Looking up the model on youtube for thermostat repairs might help the new owner repair it and get a few more years, although an older less efficient unit, with a repaired thermostat it might not run 24/7 and use fewer KwHr?