I removed one of these star grounding units - hard to gain access to properly align the screwdriver due to all the wires - I'm afraid of wires.....

Anyway after removing one, that looked good before I removed, I decided instead to simply remove each ground wire and re-install as a way of cleaning these contacts up.....

My gauges are working for the moment so it may have worked - or after some time they may not work AGAIN....

Anyway thanks for all the help....