I would check to make sure that the contacts of whatever switches make the reset coils fire are clean and making good contact, just to make sure there's enough current getting to the coils.

Are the undersides of the metal arms that go through the drops and actually lift them badly worn? That bar that presses on the underside of the metal arms to lift them can wear pretty deep divots in those arms....sometimes not evenly. It sounds like you've already loosened those hex screws that hold the coils in place and played with changing their position.

It never hurts to replace sleeves, but if you're not feeling any friction as the plunger moves in and out, they're probably OK.