Well, it turned out that most of the problem reported yesterday was the outboard end of the bushing in the control column. Its surface was way off of normal from the axis of rotation. I blocked up a "filing jig" and trued it up and that part of the problem was cured.
After installing it back in the fuselage frame, I soon found out that snugging up the mounting bolts created much the same issue - irregular forces were required to move the stick fore and aft; not near like before but unacceptable just the same. This was driven by the mounting tabs that were not co-planar and their weld beads. That led to more filing, bending and shimming with washers but the deed was done.
Next, I got the flap/aileron mixer installed and shimmed with washers.
