Obvious derivative would be two cores inside each other. Outer core follows the inner core some ten degrees and the opportunity to test pins is gone when you te

Obvious derivative would be two cores inside each other. Outer core follows the inner core some ten degrees and the opportunity to test pins is gone when you tension the inner core. This might be more robust than that sliding thing. Except the "stack of thin wafers" disappears when the lock wears out. But then, alas, the outer core could made of short rings. Rings must move in unison, and LPL can not tension them all at the same time. "Stack of wafers" not needed. (And thus I accidentally invented combination of disc lock and pin lock. The inner pin lock gives solution the outer disc lock. Patent not pending.. :-)