If I were to go with the "letter of authenticity" option, I would want that letter to say specifically the LE number, and to say specifically that the LE watch came from the factory in error with the non-numbered case back. I would want this letter signed off by Omega, not just the OB, which may or may not be owned by Omega. And I may even want two copies of the letter (to store in different locations), just to improve the liklihood that the letter lasts as long as the watch.
I would not be at all satisfied with only an acknowledgment by an OB that it's a legitimate LE Speedmaster, because that wouldn't explain the existence of the wrong case back.
My opinion is that if the letter contains the right info, that the watch would be highly unique and would have an interesting story. Maybe a one-of-a-kind letter from Omega.
My guess, though, is that the OB (or a customer visiting the OB) damaged the case back and the OB replaced it with a service case back, so you won't be able to get that cool letter from Omega. If that's the case, then just wait for one with a numbered case back, or have Omega send a numbered case back with correct number for the watch in question.
Click to expand...