There is a rubber gasket ring that goes around the movement module that keeps it jammed into the outer case. They shred after a couple of remove/replace cycles. Will try and find my spares.
"I was going to the worst place in the world, and I didn't even know it yet. Weeks away and hundreds of miles up a river that snaked through the war like a main circuit cable – plugged straight into Kurtz. It was no accident that I got to be the caretaker of Colonel Walter E. Kurtz's memory – any more than being back in Saigon was an accident. There is no way to tell his story without telling my own. And if his story really is a confession, then so is mine." What a rugged and usable vintage divers watch! Ref. 6105-8110 from 1974.