Flex in Blanik Vertical Stab

Our club Blanik L-13 has on several occasions had the lower rudder hinge
lift out of the bearing. This results in the rudder cables (under tension)
pulling the rudder forward so that it rubs on the Vert Stab spar. Today
when we took it to the shop, the AP looked it over and determined that the
vertical stab could rock forward slightly. Since the rudder is held in
place vertically by the top hinge, when the stab rocks forward, this lifts
the rudder and allows it to come out of the lower bearing.

Once solution is to reinforce the rear of the fuselage to keep the vert stab
from rocking forward. The price quoted is almost more then the Blanik is
worth. We're waiting for replies from other Blanik repair shops to see if
there are alternatives.

Has anyone else experienced this with an L-13? If so, how was it resolved?

Thanks,
John Scott