Unless I misunderstood the questions/assertions the numbers favor a slightly offset alignment. Whereas the servo arm and control arm are not 90 degrees to one another. If while at neutral the arms are 90 degrees to one another you realize exaggerated numbers in one direction as opposed to the opposite direction of travel.

Sizam

How are you netting 90 degrees of servo arm travel? Is this the total number of the travel arc lock to lock or in one direction?

If you'd prefer to forgo all the arm length, offset and what not math, there is a down and dirty method of calculating the realized numbers...

Simply accurately measure the degrees of rotation of the servo arm in one direction from neutral, and then measure the control surface deflection degrees of rotation. Then divide servo arm numbers by the latter and then multiply by the servos rated torque...

So if your getting 45/40=1.12, 1.12x100=112oz-in