Your idea a few posts back to study the angular setup of the earlier model is a very good one. As I mentioned before the need for downthrust is linked to this angular setup. The CG also being related to the angular setup.

Remember that if the elevator is not on the zero line with the stabilizer then you have to measure the angle of the tail using the leading edge of the stab and the trailing edge of the elevator as your chord line. At that point the deflected elevator makes the overall surface act like a cambered airfoil with this new chord line as the base angle. So it is important to factor in this trim on the controls when measuring these angles.