A customer brought the rudder from his Skyfox Gazelle to get my opinion on its serviceability.
I was informed that the Gazelle has a known problem with the rudder, so it was worth a look.
On first inspection a tiny amount of movement could be felt between the rudder cable attachment tube and the vertical rudder post.
I removed the fabric and found that the vertical post was cracked and going to completely fail eventually.
This repair was done to FAA AC43.13.
All good now.