rear end woes

I agree- too much wine too much slop.
Just go by the book- tear it down and reassembly starting from scratch. No easy way about it if you want to save those gears.

Once apart you will know using the wear patterns if they are good or worn beyond use.

And without pictures - on here... you won’t get any info because most of us do not have a crystal ball to see inside your axle.
Keep us posted and good luck- you can do this.