Hello, I'm looking at a LeCoultre Master Mariner. This has a 14k gold case and bumper movement. The caseback appears to be a standard screw on type. Were all watches marked "Master Mariner" water-resistant? I've seen casebacks for these that indicate the use of a special wrench. Were they all that way (even the earliest bumper types)? Trying to determine if the re-dial added Master Mariner just for fun! Dirik Lolkus