Combines levelling concaves

That is one area to look, but more important is to measure from the rotor bars to the concave and make sure this dimension is the same front to rear. Also, check the dimisions from the left side of the concave to the rotor bars. This has a huge impact on threshing and shoe loading. More than pinch point in my opinion.

These two bars being parallel has nothing to do with weather the concaves are parallel with the rotor. To level the concaves you should raise the front and back of the concaves up while tuning the rotor by hand. When the front and back concave touch a rotor bar at the ame time the rotor is level. Back the concave off about a round and set the gauge at zero and you have it.