Jason and I measured the support tube nozzle flange location with respect to the chamber center position.
Measurement was shot to the back side of the flange where it joins the the nozzle tube.
The results are:

Right side angle is 120deg, 34', 12" at a horizontal distance from the total station of 2356mm.
Left side angle is 59deg, 19', 17" at a horizontal distance from the total station of 2354mm.
 Difference is Y- 1.9mm.