[ Ref. John Rodriguez in 190204 MMDigest ]

Maybe there is a support strap still attached.  I had a similar problem
to yours until I found a strap attached to the player action on one end
and the other end screwed to the back of the piano key bed.  It was lots
of fun to get at -- behind the piano action and behind and under the
keys.  I think it was in the bass-tenor break area.  Look there.

Good luck,

Jeff Davis