You seem to have sufficient horizontal deflection, but vertical deflection is wonky. I'm not sure I fully understand the history you provided -- are all the components from the Classic II, or is there now a hybrid of SE/30 and Classic II bits? The reason I ask is that the deflection yoke (the assembly that sits around the neck of the CRT), to which the four "power supply" wires (they're actually the horizontal and vertical deflection signals), is a very different beast in the Classic II, from what is in the SE/30. Mixing-and-matching can result in a variety of pathological behaviors.