OK - I've gone a bit deeper - managed to disconnect the control wire (from the airflow knob) and the selector still does not want to go to the VENT position.
This seems to indicate the problem lies in the knob mecanism rather then the set of levers that open/close the air passages.
I'm currently stock and not able to remove the climate control box (with the 3 knobs). 2 things still to remove that I have not found a way so far:
1) 1 remaining main electrical connector at the back center of the box (ANY IDEAS HOW TO UNPLUG IT

)
2) the control wire for the airflow knob is also held (pinched) at the upper right corner - there is an opening in the front where you see the wire - maybe will try to push it out thru a small slot/opening.
Hopefully if I can these 2 things sorted out - I should have the control box in my hand ....