It really is a fine line between having no blade play, and having it smooth.
Sometimes it's okay to take a deep breath, put the parts neatly away, then come back to it later.
If you decide to take it apart again, clean the washers and smooth them out with some fine paper or a strop.
Apply a little lube to both sides of the washers. Take your time when putting it back together. I usually just take the blade out unless it's a Barrage, but if you are removing the scales then make sure it all clicks back into place. Misaligned screws can make all the difference.
With the pivot, I start out with a super loose blade, then start dialing it in bit by bit. You should hit that sweet spot.
Have had a few 710's, Shot show grip and a Contego that I thought would have to go back. Ended up fixing them and they are so smooth, centered and solid.
Cheers
Edit.
Just realized you have a black coating. Try and remove coating from pivot area.