From your description it sure sounds like it’s colliding with something. Here are few things you may want to check if you haven’t already.
1. Contact between balance arm or rim and mainsprng barrel. Make sure the barrel cap is seated in place and if it is make certain that the barrel is running true (not leaning over).
2. Check that Balance is running true ie. arms/rims bent or twisted off plane. Also check that balance is not riveted off axis and that it is not loose on the staff.
3. Check that cap jewels are seated tight in place and not allowing the balance to sit too low. This might allow the balance to move down far enough to drag on the plate or barrel.
4. Any screw that may be too long coming up through the plate or down through the balance cock. I don’t think there’s any screw that could cause this on the 1883 but…
5. Check in the Dial Up position to see if the interference stops.
6. Loose balance screw or wrong screw in a balance rim. Probably not an issue with the 1883 as the balance cock foot to balance clearance is pretty wide but this does happen with many other watches so good to have on a check list.
7. Hairspring is laying flat.
8. Anything else I’m missing like hairspring stud not secure in balance cock or not pinned tightly to stud etc.
Let us know what you come up with Tom.