Just a suggestion, but you might want to try getting all three back to about the center of each of their ranges and go through the procedure again. Since the resistors are multi-turn without real 'stops' it can be a little tricky. They have a subtle click to them when they are at the end of their range. I'm not sure if they are 10, 15 or 20 turn types.?
R27 is the I-Q balance control and should have the greatest effect on the null. The other two resistors help balance out high and low sides of the audio bandpass.?
I hope that helps!
--Al
WD4AH
