The last bit of rework was to remake the bottom section of the control column. The original restricted the forward movement of the control column somewhat. The lower section below the main forward/aft pivot is designed to narrow left/right from a bend half way down to the joint with the elevator pushrod where the two sides are welded together. In the original version this narrowing section was interfering with the square tubing that runs diagonally up to provide the control column pivot as the control column was moved forward. The new version has the taper starting 1/2" lower than the original which affords greater forward movement. 
