The crane latch pivot is staked. That is why it only backed out ¾ turn and went unnoticed during inspections. The loss of the interlock function was first discovered when a friend and I were showing off the differences between the Super Blackhawk and the Redhawk to another friend, comparing Ruger’s single action loading gate safety to the double action interlock. When the interlock proved intermittent, the Redhawk was set aside and not shot until fixed. The "gradual, progressive" nature I described is the result of multiple disassembly/reassembly cycles and a lot of experimentation in my attempt to diagnose the problem. I do not normally attempt to cock a revolver or cycle its trigger while the crane is unlatched, nor do I normally try to open the crane while the hammer is at full cock. Discovering the flaw came only when I wanted to demonstrate the interlock. The interlock, at least in my case, is Ruger’s answer to a problem that does not exist. The movement of the pivot did not compromise lockup or timing, and had the pivot dropped completely from the gun, the gun have would failed safe: the latch would have ceased to release the crane. In a hunter/plinker the result would have been a nuisance only. In the end, I answered my initial question - it was nothing to worry about and a trip to a smith would have cost money better spent elsewhere.