The only problem is that the entire stack has either shifted to the
left or the right.  Just loosen the thumb screws that hold the stack
up to the keybed, then move the stack so that the stickers hit directly
on the center of the keys.  There might be a bracket on the right side
of the piano that holds the stack in place but I have found this
missing on many of these players.

Pete Knobloch
Tempe, Arizona