The bell on my 1947 Underwood SS doesn't ring when it's supposed to. If I situate the left margin guide/bell ringer to the right position, when the carriage goes over it, the bell will ring. None of the pieces are stiff, but the part the arrow is pointing to doesn't seem to have enough momentum to return to the correct spot. The only thing I did that might've done something was take out the screws that hold the bar for the margin guides in place. What can I try to fix it?