The damper is to reduce side-to-side oscillations (shimmy). It won't make the car pull. Try feeling for a difference between throttle on and throttle off. That would point you toward the rear end; thrust links or camber links.
Could it just be the crown of the road, giving you a pull to the right? Try it on different types of roads. Also, if the alignment shop isn't familiar with MB, there are some special things
for MB alignments. What's new?
Best of luck,