RobertWe had a great Southeast Seminar last night presented by Don Mannino. Those under lever capstans are for adjusting the timing of the damper lift by the key end, not the damper tray.
I know that doesn't hep you in your search, but it might help you when you go to regulate the damper Ader the repair.
im guessing you'll need to order a new under lever unless you can find a used one to scavenge from this list.
Good, Better, Best