I've heard that a hammer could fix that. I guess (have never done it) you could clamp the pivot area between two pieces of wood (1/4" think or so?) and give a gentle tap with a hammer on one side and see how it works out.
What Ted suggested works fine. I have tightened an FRN Delica with this method with no problems. Not sure how easy it will be with SS versions, the FRN is more predictable because of the ball capped rivets.