Hello Matt
It sounds like the "bronze nut" is comming to the end of the thread or the end of the tube before all of the weight of the keel is resting on the cheek blocks and the top of the fixed keel.
This could be caused if the wire strops were too short.
If you want I can measure mine as I have the old pair lying around somewhere.
Mike Edwards
Seal 28 "Aztec"
Mike Edwards
Seal 28 "Aztec"