To me you got lots of different circuits being affected and all have to have a ground.

You might want to check back onto the main harness a look in the dark for those black wires from it! I know their tough!

It might be one of those "Y" circuits or one of those WHY did that break wires😱

I am talking about the one that disappear behind the relays from tachometers and clocks or radios and bend down behind the lower console.
They are fastened under a sheet screw on the upper left corner.
One might have weaken or broken from a repair elsewhere?
The Instruments lights and those console lights are for sure grounded on there, so may the harness was too!

Just thought if I spent a moment thinking of it, you might too!
😐 good luck! I hope you find it quick, whatever it is!
Phil