In my crude drawing below, it’s pretty clear to me how turning the eccentric moves the lower control arm mounting point side to side to adjust camber, and it looks to me that you can get the same amount of camber adjustment (just reversed) with the bolt head in either the top OR bottom half of the bracket. But I’m wondering whether the control arm mounting point also moves up and down along the circle traced by the bolt head as you turn it. I ask because on my 68, the bolt head on one side is in the top half of the bracket and the other side, it’s in the bottom half, meaning that one of my control arms may be mounted higher than the other? 
The bolt can only move sideways in a slot, not up and down. In your drawing, you have the bolt head above the center line of the arm, and that is what is making you think it ccan move up and down, it can’t, it can only move from side to side in the slot.
With what you have illustrated I would be concerned that the …bolt, bracket or bushing has severe damage.