Varying spark, out of ideas

I have not. If I am understanding correctly, this is the distributor drive shaft bushing inside the block by the back of the cam, correct? I check the teeth for excessive wear by using a screwdriver to rotate that gear as described by another poster and found little rotational movement. The gear did rock back and fourth a bit which I am now thinking could indicate wear on the bushing.

I also mentioned the possibility of mechanical advance springs being damaged and letting the flyweights bounce around.